Direct Variation

Topics for Today:

Although we discussed direct variation several months ago, as we discuss related topics, I felt it was a good idea to revisit this topic.  Direct variation refers to how two variables are related to each other.  In algebraic terms, a function in the form of y = kx, where k ≠ 0, is a direct variation.

This function is similar to our slope-intercept form of a line (y = mx +b).

For direct variations, there is no y-intercept, and all of these functions must pass through the origin (0, 0).  We are effectively dealing with part of our slope-intercept form, y = mx.

For direct variations, we use the variable "k" to represent the slope, which is also our constant of variation.

Vocabulary:  direct variation, constant of variation

Sections Covered in Textbook:

5-5: Direct Variation (pages 261-266)

Resources & Tutorials:

1) What is the formula for direct variation?
2) What is the constant of variation?
3) How do you use the formula for direct variation?

Solving Radical Equations

Topics for Today:

We added to our equation solving tools today by working with equations containing radicals.  To solve these equations, we must isolate the variable on one side of the equation.  Once we do that, we can "undo" taking a square root by squaring both sides.  We must be careful when squaring equations so that our process does not result in extraneous (extra) solutions.  It's always best to check our solutions to make sure they satisfy the original equation.  As with many other equation types, we may have a situation where our equation has no solutions.  In Algebra I, we do not work with imaginary numbers (in our class they are the square roots of negative numbers), so if we encounter any of these, our equation has no real solution.

Vocabulary: radical equation, extraneous solution

Sections Covered in Textbook:

11-5: Solving Radical Equations (pages 607-612)

Resources & Tutorials:

1) How do you solve radical equations?
2) How to solve a radical equation with a binomial radicand.

Conjugates and Other Roots

Topics for Today:

We finished our discussion of operations with radical expressions today with a method to simplify fractions with radical operations in the denominator.  We discussed the topic of conjugates to rationalize denominators that fall into this category.

We also discussed different roots other than square roots, and how to find them.

Vocabulary:  conjugate, cube root

Sections Covered in Textbook:

11-4:  Operations with Radical Expressions (pages 600-605)
**Other Root Functions are not in our book.

Resources & Tutorials:

1) Divide by Conjugate Method
2) Math is Fun: Cubes and Cube Roots (not a video).
3) How do you find the cube root of a perfect cube? 
4) Fourth Roots

Operations with Radical Expressions Part 1

Topics for Today:

Radicals have some similar properties as variables when we manage them in equations and expressions.  Just like variables, we can only combine radicals that are like each other.  When we combine or take away (add or subtract) radicals, we may only do so if our radicals are like each other.

We can only combine like radicals, and sometimes we need to simplify first, and then we may have like radicals that we can combine.  

The distributive property also works with radicals, including double distributing (otherwise known as FOIL).  

Finally, we discussed how to manage fractions that have binomials in the denominator that contain radicals.  We can multiply by the conjugate, which results in the difference of squares and the removal of the radical.   (*We did not get to this concept today - we will tackle it tomorrow.)

Vocabulary: like radicals, unlike radicals

Sections Covered in Textbook:

11-4: Operations with Radical Expressions (pages 600-606)

Resources & Tutorials:

1) How to add radicals together with like radicands?
2) How do you subtract radicals with like radicands? 
3) How do you subtract radicals with different radicands? 
4) How to use the distributive property with radicals?
5) How to "FOIL" with radicals
6) Divide by Conjugate Method (will do tomorrow)

The Distance and Midpoint Formulas

Topics for Today:

We continued with applications of square roots today and how it applies to geometric concepts.  The distance formula can be used to find the length of any line segment that is plotted on a coordinate plane.  The distance formula is a direct application of the Pythagorean Theorem.

The midpoint formula is another geometric concept.  The midpoint of a line segment divides that segment exactly in half.  To find the midpoint of a line segment, we are basically taking the average of the coordinates of the endpoints.  

Vocabulary:  distance formula, midpoint, midpoint formula

Sections Covered in Textbook:

11-3: The Distance and Midpoint Formulas (pages 591-597)

Resources & Tutorials:

1) What is the distance formula?
2) What is the midpoint formula? 
3) How to find the coordinate of a midpoint given endpoints.

The Pythagorean Theorem

Topics for Today:

A special relationship exists with the lengths of the sides of a right triangle.  A famous Greek mathematician and philosopher by the name of Pythagoras proved its existence many years ago, although there is evidence that the ancient Babylonians knew of the relationship many centuries before.

The theorem states that if you have a right triangle (a triangle with one 90-degree angle), that the sum of the squares of its sides is equal to the square of the hypotenuse (the longest side).

Vocabulary: hypotenuse, leg, Pythagorean Theorem

Sections Covered in Textbook:

11-2: The Pythagorean Theorem (pages 584-590)

Resources & Tutorials:

1) What is the Pythagorean Theorem?
2) If you have the sides of a triangle, how can you tell if it's a right triangle?
3) Math is Fun - Pythagorean Triples

Simplifying Radicals Parts 1 and 2

Topics for Today:

We began our unit on radical expressions and equations today with an exploration of the process of simplifying radicals.  Just like other mathematical expressions, we have rules for what constitutes a radical in "simplest" form.  We will be spending two class periods learning about simplifying radicals. 

Like other algebraic concepts, there are properties that apply to radicals.

Vocabulary:  radical expression, rationalize

Sections Covered in Textbook:

11-1:  Simplifying Radicals (pages 578-583)

Resources & Tutorials:

1) What is the product property of square roots?
2) How do you use the product property of radicals to simplify a radical?
3) How do you multiply radicals?

Vertex Form of a Quadratic Function

Topics for Today:

Today we explored the vertex form of a quadratic function.  Just like linear functions that have multiple forms that are each useful for certain things (slope-intercept, standard, point-slope), quadratic functions also have multiple forms (standard and vertex) that are used for different purposes.  Up to this point we have only used standard form.  

The vertex form of a parabola is very useful because it is very easy to locate the parabola's vertex, and when exploring families of graphs it is easy to see how translations (vertical and horizontal shift as well as vertical shrink or stretch) change the size and location of the graph.  

Sections Covered in Textbook:

Concepts pulled from outside materials

Resources & Tutorials:

1) How do you convert a quadratic equation from vertex form to standard form?

2) Finding the vertex of a parabola in standard form

Completing the Square

Topics for Today:

Today we explored the final way to solve quadratic equations: completing the square.  We can apply our knowledge of perfect square trinomials to set our equations up so that When we take an equation of x^2+bx+c=0  and apply algebraic properties including our perfect square trinomial pattern to solve it, we call this process “completing the square”.

We complete the square to solve so that we are able to take the square root of each side of the equation to produce our solutions.  (So far we have used factoring and the quadratic formula to solve these equations).

Here is an example of completing the square:

Sections Covered in Textbook:

10-6: Completing the Square (pages 541-546)

Resources & Tutorials:

1) Solve by completing the square
2) How to use a shortcut to factor a perfect square trinomial

Using the Discriminant

Topics for Today:

The quadratic formula can be used to find the solutions of any quadratic equation that is in standard form.  There is a piece of the formula called the discriminant that is very useful to determine the types of solutions that our equation will have.   Additionally, we can tell if our equation is easily factorable by looking at the discriminant.  If the discriminant is a perfect square, we have an easily factorable equation.

Sections Covered in Textbook:

10-8: Using the Discriminant (pages 554-558)

Resources & Tutorials:

1) What is the discriminant?
2) How do you use the discriminant to find out the number of solutions?

Using the Quadratic Formula

Topics for Today:

One method that can be used to solve any quadratic equation is the quadratic formula.  The quadratic formula uses the coefficients from the equation to find the values for x when y is zero.  It is highly recommended that students MEMORIZE the quadratic formula.  The quadratic formula works even when we don't have real solutions (yes, there is such a thing as an imaginary number - stay tuned - you'll become very familiar with imaginary numbers in Algebra II). 

Vocabulary: quadratic formula

Sections Covered in Textbook:

10-2: Using the Quadratic Formula (pages 547-553)

Resources & Tutorials:

1) What is the quadratic formula?
2) How do you solve a quadratic equation using the quadratic formula?

Factoring to Solve Quadratic Equations

Topics for Today:

All of the work we have done on factoring has led to today's topic of solving quadratic equations by factoring.  We talked about the zero-product property (when multiplying, if one factor is zero, then the equation equals zero), and how we use it to find our solutions (also called roots or zeroes). 

An example of an equation that requires several steps to solve is included here:

Vocabulary:  zero-product property

Sections Covered in Textbook:

10-5: Factoring to Solve Quadratic Equations (pages 536-540)

Resources & Tutorials:

1) What is the zero-product property?

2) How do you use the zero product property to find solutions to an equation?

3) How do you solve a quadratic equation by factoring?

Solving Quadratic Equations

Topics for Today:

Solving quadratic equations was the topic of the day.  We solved these equations by graphing and by using algebra.  For quadratic equations, we have three possibilities for our solutions:  we may have two solutions, one solution, or no REAL solutions.  The rules of algebra still apply when solving numerically - whatever we do to one side of the equation, must also be done to the other side to keep the truth of the equals sign.  Students were also reminded that squaring and taking the square root are inverse operations. 

Sections Covered in Textbook:

10-4: Solving Quadratic Equations (pages 529-534)

Resources & Tutorials:

1)  How do you solve a quadratic equation with two solutions by graphing?

2)  How do you use the square root method to solve a quadratic equation with two solutions?

Finding and Estimating Square Roots

Topics for Today:

Today we discussed perfect squares and square roots.  Squaring and taking the square root are inverse operations.  Students will be asked to memorize the common perfect squares, and there is a Quizlet set that should hopefully make learning them fun.

Vocabulary: square root, principal square root, negative square root, radical, radicand, perfect squares

Sections Covered in Textbook:

10-3: Finding and Estimating Square (pages 524-528)

Resources & Tutorials:

1) What is a perfect square?
2) How do you find the square root of a perfect square?
3) How do you find the square root of a fraction?
4) How do you estimate a square root of a non-perfect square?

Quadratic Functions

Topics for Today:

Quadratic functions are still the topic of the day.  Today we worked with the axis of symmetry and used it to find our vertex.  Because parabolas are symmetric, we are able to find points on one side of the axis of symmetry and reflect them to the other side of the axis of symmetry.  Once we have the vertex, and a few points on either side of the axis of symmetry, we can easily draw our parabola.

Sections Covered in Textbook:

10-2: Quadratic Functions (pages 517-523)

Resources & Tutorials:

1) How do you find the axis of symmetry?
2) Find the axis of symmetry and your vertex

Exploring Quadratic Graphs

Topics for Today:

Today we began our work on quadratic functions.  Quadratic functions, simply stated, are functions that have a variable with the highest degree exactly equal to two.  We looked at the standard form of a quadratic function and looked at graphs of different parabolas.

Vocabulary: quadratic function, standard form of a quadratic function, parabola, axis of symmetry, vertex, minimum, maximum

Sections Covered in Textbook:

10-1: Exploring Quadratic Graphs (pages 510-516)

Resources & Tutorials:

1) What is a quadratic function?
2) What is a parabola?

Summary of Factoring

Topics for Today:

We have completed work in Chapter 9, and are reviewing all the concepts for factoring.  Students practiced decision-making, and which different processes we can use to factor polynomials. 

Next up - Review and Chapter 9 Test.  

Sections Covered in Textbook:

No new sections covered.

Resources & Tutorials:

1)  Factoring Decision Tree

Factoring Special Cases

Topics for Today:

We are back to pattern recognition for factoring.  When we multiplied binomials by squaring them or by multiplying a difference, we noted a pattern for the resulting products.  Today, we worked backward from the trinomial (in the case of perfect square trinomials) or the binomial (in the case of difference of squares) to determine the two binomial factors. 

Students are reminded that now would be a good time to memorize the common perfect squares.  We also talked about square roots in the context of being the opposite of squaring numbers.  We'll deal with radicals a little later on, in May. 

For perfect square trinomials, students should be asking the questions:

• Is the first variable term a perfect square?
• If yes, is the constant term a perfect square?
• If yes, is the middle term equal to two times the square roots of the first and third terms?

What about factoring difference of squares?  We have another pattern to follow for this type of polynomial.  For the difference of squares, students should be asking the questions:

• Is the variable piece a perfect square?
• Is the constant piece a perfect square?
• Is the operation being performed subtraction?

Sections Covered in Textbook:

9-7: Factoring Special Cases

Resources & Tutorials:

1) How to use a shortcut to factor a perfect square trinomial
2) How do you factor using the difference of squares

Factoring Trinomials Part 2 - Split the Middle

Topics for Today:

We expanded our discussion today to include factoring polynomials where the leading coefficient is not 1.  We used the product-sum game to work with factors so we could "split the middle" of the equation, and then factor by grouping.

Sections Covered in Textbook:

9-6: Factoring Trinomials of the type ax² + bx + c (where a ≠ 1)

       (pages 486-489)

Resources & Tutorials:

1) Factor a trinomial using A-C method
    (This is a different method from what was introduced in class.)
2) Factor a trinomial with a > 1
    (This method is more like what was introduced in class.)

Factoring by Grouping

Topics for Today:

We continued our discussion of factoring polynomials today with a brief review of the Greatest Common Factor (GCF) and how we can divide the GCF out of a polynomial by using the distributive property in reverse.

Over the next several days we will tackle factoring of many different scenarios.  Factoring by grouping is a method that is used to deal with polynomials that have more than three terms.  Most people are familiar with factoring trinomials (3-terms), so when we are faced with more factors, our options are limited for how we can proceed.

In factoring by grouping, we will take two sets of two terms and pull out/factor out a GCF.  The goal is to have a leftover quantity for both groups that match one another.  If we do get our desired outcome, then we can further factor out the quantity, leaving us with a product of two binomials.

Sections Covered in Textbook:

9-8:  Factoring by Grouping (pages 496-501)

Resources & Tutorials:

1) How do you factor a 4-term polynomial by grouping?
2) The easiest way to factor a polynomial with four terms by grouping.

Factoring Trinomials Part 1

Topics for Today:

Our discussion about factoring moved to factoring trinomials today.  We played a game called the "Product-Sum" game where we analyzed a set of two numbers to see what factors create both a product and a sum.  We then related this game to how we factor trinomials.  We will always be looking to create a product (answer to a multiplication problem) and a sum (answer to an addition problem) at the same time.  Notice the coefficient that precedes the first term is one.  We'll address scenarios where the leading coefficient is NOT one in a future lesson.

Sections Covered in Textbook:

9-5: Factoring Trinomials of the type ax² + bx + c (where a=1)
       (pages 481-485)

Resources & Tutorials:

1) How do you factor a trinomial?
2) How to factor quadratic equations.

Multiplying Binomial Special Cases

Topics for Today:

We expanded our discussion on multiplying binomials today to include some common patterns:  squaring sums, squaring differences, and the product of a sum and a difference.  For each of these cases, we can always use the distributive property or FOIL methods to expand the product; however, as with many aspects in mathematics, recognizing patterns can save a lot of time.

Sections Covered in Textbook:

9-4: Multiplying Special Cases (pages 474-479)

Resources & Tutorials:

1) What is the formula for the square of a sum?
2) What is the formula for the square of a difference?
3) What's formula for the product of a sum and a difference?

Multiplying Binomials

Topics for Today:

Our topic for today was multiplying polynomials.  We focused our time mostly on multiplying two binomials together (recall that a binomial is the sum or difference of two monomials).  We focused on the number of individual products to ensure we did not leave any steps out.  Most people are familiar with the FOIL method for multiplying two binomials:

Sections Covered in Textbook:

9-3: Multiplying Binomials (pages 467-472)

Resources & Tutorials:

1) Multiply Binomials using the Distributive Property
2) Multiply Binomials using the FOIL method
3) How to Multiply Trinomials 

Multiplying and Factoring Polynomials

Topics for Today:

We explored multiplying a monomial by a polynomial today and doing the reverse by factoring out the greatest common factor.  Multiplying and factoring are inverse (opposite) operations of each other.

Vocabulary: Greatest Common Factor, GCF

Sections Covered in Textbook:

9-2: Multiplying and Factoring (pages 462-465)

Resources & Tutorials:

1) How do you multiply a monomial by a polynomial?
2) How do you find the Greatest Common Factor (GCF) of monomials?
3) Factoring Monomials from Polynomials

Adding and Subtracting Polynomials

Topics for Today:

Today we began our unit on polynomials with some definitions.  We also worked on adding and subtracting polynomials.  Like working with any variable expressions, we must always look for like terms when combining their components.  Variables raised to different powers cannot be combined by adding and subtracting.  One last concept to keep in mind is that when subtracting polynomials, you must subtract each piece of the polynomial; that is, the subtraction must be distributed to each piece of the polynomial and not just its first term.

Vocabulary:  monomial, degree of a monomial, polynomial, standard form of a polynomial, degree of a polynomial, binomial, trinomial

Sections Covered in Textbook:

9-1: Adding and Subtracting Polynomials (pages 456-461)

Resources & Tutorials:

1)  What is a monomial? 
2)  What is a polynomial? 
3)  How do you find the degree of a polynomial?
4)  How do you add polynomials? 
5)  How do you subtract polynomials? 

Division Properties of Exponents

Topics for Today:

Today we tackled the last property of exponents that deals with division.

When dividing powers with the same base, we can simply subtract the exponents.  When dividing monomials, we must match up like bases with each other, and deal with them separately.

Sections Covered in Textbook:

8-5: Division Property of Exponents (pages 417-423)

Resources & Tutorials:

1) What's the quotients of powers rule?
2) How do you divide monomials using the quotients of powers rule?
     (*This video leaves a negative exponent - that is NOT simplest form!*)

More Multiplication Properties of Exponents

Topics for Today:

Today we reviewed the topics relating to exponents and exponent rules, including scientific notation.  We expanded our topic of multiplication of powers to include raising a power to a power, as well as taking a monomial to a power.  When a monomial (a number, a variable, or a product of a number and variable - this also includes whole number exponents) is raised to a power, each element of that product must be raised to that power.

Sections Covered in Textbook:

8-4: More Multiplication Properties of Exponents (pages 411 - 415)

Resources & Tutorials:

1) What the power of a power rule?
2) How do you take a monomial to a power?
3) More on the power of a product rule.

Multiplication Properties of Exponents

Topics for Today:

Today we discussed how to manage multiplying powers with the same base.  We looked at several examples as well as explored how to multiply numbers together that are in scientific notation.  In summary, when multiplying powers with the same base, just keep the base and add the exponents together.  This process works for both positive and negative exponents.

Graphic Credit: https://www.onlinemath4all.com/multiply-powers.html

Sections Covered in Textbook:

8-3: Multiplication Properties of Exponents (pages 405-410)

Resources & Tutorials:

1) What is the product of powers rule? 
2) How do you find the product of powers? 
3) How do you multiply numbers using scientific notation? 

Scientific Notation

Topics for Today:

Today we used exponents in a practical way when we learned about scientific notation.  Scientific notation is simply a way to write very large and very small numbers that follow a few rules.

Simply stated, scientific notation is the product of a number and a power of 10 that follows the format: 

a x 10ⁿ  where n is an integer and 1 ≤ a < 10

Image credit: https://pt.slideshare.net/jessicagarcia62/compute-with-scientific-notation/6?smtNoRedir=1

Vocabulary:  scientific notation

Sections Covered in Textbook:

8-2: Scientific Notation (pages 400-404)

Resources & Tutorials:

1) What's scientific notation? 
2)  How do you convert decimal notation to scientific notation? 
3) How do you convert from scientific notation to decimal notation? 
4) How do you order numbers in scientific notation? 

Zero and Negative Exponents

Topics for Today:

We began a discussion about powers, bases and exponents today, and focused on bases with a zero exponent as well as negative exponents.

Summary

• Any non-zero number raised to the zero power equals one!
• Negative exponents are fractions.  If a factor is moved up or down in a fraction, the sign of the exponent is changed.  

Sections Covered in Textbook:

8-1: Zero and Negative Exponents (pages 394-399)

Resources & Tutorials:

1) What do you do with a zero exponent? 
2) What do you do with a negative exponent?

Applications of Systems Part 2

Topics for Today:

Yesterday we began to tackle applications of systems of equations.  Basically, we are going to be solving story problems that have two unknowns, requiring us to write two equations to solve them.  These types of problems can be categorized and patterns emerge as we see more and more of these types of problems.  

We did a Desmos activity today that helped us with building equations and solving them.  

Sections Covered in Textbook:

7-4: Applications of Linear Systems (pages 362-368)

Resources & Tutorials:

1) How do you solve a word problem using two equations? 
2) Simple word problem resulting in two equations (not a video)

3) Desmos Activity on Systems of Equations (Login with Google)

Applications of Systems

Topics for Today:

One of the things that is most annoying about Algebra I is the focus on the processes and procedures for solving equations, inequalities, and problems.  Most of the time we are focused on process rather than application, but this foundational toolset is critical to solving problems requiring higher thinking and reasoning.

Today we used our knowledge of solving systems of equations to solve some real-world problems.  Typically students lack confidence when solving story problems, although it is these very problems where we get to use all the skills we have been building.  As I continually reinforce to our students, mastering Algebra requires repetition and practice, like any other skill we hope to master.  The only way to become competent and confident solving story problems is to do them -- LOTS of them.

The main thing to remember when solving the linear systems we have been working on is that if we have two variables, we will need two equations to solve.  The same would be true for three variables (a topic for Algebra II where you need three equations).

For these story problems, first, we must identify and define our variables.   Second, we will analyze the given information and write our equations based upon the given information.  Once we have our equations, we can determine the best method to solve the system.  Finally, we must look at the question that was asked and make sure that our solution answers the question, that we have the correct units, and that our answer makes sense.

Many of these story problems follow a pattern, and identifying the pattern makes the problem easier.  For this topic, we normally have several patterns to choose from:  mixtures, distance-rate-time (these can come in many forms, and can deal with things like water and wind currents that speed up or slow down the traveler), and break-even.

Sections Covered in Textbook:

7-4: Applications of Linear Systems (pages 362-368)

Resources & Tutorials:

1) How do you solve a word problem using two equations? 
2) Simple word problem resulting in two equations (not a video)

Systems of Linear Inequalities

Topics for Today:

We expanded our discussions about linear inequalities and systems to include the topic of systems of linear inequalities.  We discovered in our lesson yesterday that linear inequalities include all the points on one side of a border.  When we combine two linear inequalities, we are going to look for where both overlap.  The only way to represent this overlap region is by graphing.  (Recall that we discussed and practiced three different ways of solving linear systems - graphing, substitution method, and elimination method.)

The solution to the system

y < 2x + 1 and

y > 1/2 x -3 

looks like this:

The red region represents the overlap,

and therefore the solution to the system.

Vocabulary:  system of linear inequalities, solution of a system of linear inequalities

Sections Covered in Textbook:

7-6: Systems of Linear Inequalities (pages 377-384)

Resources & Tutorials:

1) What is a system of inequalities? 
2) How do you solve a system of inequalities by graphing?

Linear Inequalities

Topics for Today:

We are still finding our way around the coordinate plane, and today we discussed how to graph the solution to a linear inequality.  A linear inequality describes a region of the coordinate plane that has a boundary line.  The solution to a linear inequality are all the coordinate points that make a linear inequality true.  The solutions to inequalities contain infinitely many more solutions than that of equations, and the same is true for linear inequalities.

Solutions to linear inequalities involve graphs.  The process for graphing linear inequalities is very similar to graphing linear equations with a few additional details.  The basic process for graphing linear inequalities is

1. Treat the inequality just like an equation.  Use the equation to graph the boundary line.
2. Determine if the boundary line is a part of the solution
• For equations that are strictly greater or less than (>  or <), the boundary is NOT included and should therefore be a dashed line.
• For equations that are greater than or equal to or less than or equal to (≥ or ≤) the boundary line IS included and should therefore be drawn as a solid line.  
3. Next, determine which side of the line the solution points fall.  The best way to accomplish this is to pick a point on either side, and test the inequality for truth.  The point that generates a true statement is on the side of the line with the solution.
4. Once the correct side of the boundary is found, shade this region to indicate where the solutions are.  

Vocabulary: linear inequality, solution of an inequality

Sections Covered in Textbook:

7-5: Linear Inequalities (pages 370-375)

Resources & Tutorials:

1. What is a linear inequality?
2. How do you figure out if the boundary is part of the graph of the inequality?

Solving Systems Using Eilmination

Topics for Today:

We are still working on systems of linear equations.  Today, we discussed elimination method, and with a system of two equations, this method is really the preferred one.

Steps for Solving Using Elimination Method

1. In your original system, make sure both equations are in the same form (standard form works best!).  Line your equations up so the variables are aligned in columns.  
2. Determine which variable should be eliminated.  Look for matching numbers and opposite signs or create them using multiplication.  You may have to multiply both equations so that you can eliminate one variable.  
3. Eliminate the chosen variable.  Solve for the other variable.  
4. Take the value you found in Step 3 and substitute it into one of the original equations to solve for the other variable. 
5. Identify your solution – it will be an ordered pair!
6. Check both original equations with the solution you found.  

 Graphic Credit: http://www.hotelsrate.org/solving-systems-of-linear-equations-by-elimination-examples/

Vocabulary:  elimination method

Sections Covered in Textbook:

7-3: Solving Systems Using Elimination (pages 353-359)

Resources & Tutorials:

1. How do you solve a system of equations using the elimination by addition method? 
2. How do you solve a system of equations using the elimination by multiplication method?
3. What's another way of solving a system of equations using the elimination by multiplication method?

Solving Systems Using Substitution

Topics for Today:

We are still working on solving systems of equations and introduced a new method today that uses algebra instead of graphing.  We have discussed the limitations of the graphing method, and why we might use algebra instead.  There are three algebraic methods used to solve systems:  substitution method, elimination method, and the matrix method.  We will learn and practice the first two; solving of matrices with systems of 2 or more equations is covered in Algebra II.

The general process for solving systems algebraically is the same.  First, we solve for one of the variables; then we substitute that solution into one of our equations to find the second variable.

For the substitution method, we follow this process:

1. In the original system, see if one variable is isolated; if not, then isolate a variable. 
2. Substitute the expression into the second equation.
3. Solve the equation for the first variable.
4. Substitute the solution found in step 3 into one of the original equations to solve for the other variable. 
5. Identify the solution as an ordered pair.
6. Check both original equations to ensure the solution works for both. 

(Graphic Credit: https://www.mathwarehouse.com/algebra/linear_equation/systems-of-equation/solve-by-substitution.php)

Vocabulary:  substitution method

Sections Covered in Textbook:

7-2: Solving Systems Using Substitution (pages 347-351)

Resources & Tutorials:

1) How to solve a system using substitution method.
2) Solving Systems of Equations by Substitution.

Graphing Systems of Equations

Topics for Today:

We are still working with graphing linear equations, but we've expanded our conversation to include systems of linear equations.  A linear system of equations is simply two or more linear equations containing the same variables.  When we deal in generic equations, we almost always use the variables x and y; however, when we use systems to solve real problems, we may define our variable with different letters that better match our problem.  For instance, if we are talking about costs and revenue, we may choose to use c and r for our variables.

Systems of two linear equations have three possible types of solutions because they are based upon where two lines intersect on a plane:  they either intersect nowhere, intersect at one point, or intersect at every point.  If there is a solution, it is represented as an ordered pair.

Summary of Systems of Equations
(Click Graphic to Enlarge)

Vocabulary:  system of linear equations, solution of a system of linear equations

Sections Covered in Textbook:

7-1: Solving Systems by Graphing (pages 340-345)

Resources & Tutorials:

1) What is a system of linear equations?
2) How do you solve a system using graphing?
3) What is a solution to a system of equations? 
4) What are the three types of solutions to a system of equations?

All About Linear Graphing

Topics for Today:

No new material was covered in class today; instead, we reviewed finding slope, using the various forms of a line, and finding parallel and perpendicular lines in preparation for our test tomorrow over the chapter.  We did not cover the last 2 sections of the chapter and they will not be on the test.

To be proficient in the concepts covered in this chapter students will need to be able to move freely among the different line forms.

Students were provided a graphic organizer that includes all the main topics from this chapter up to this point.  We have one more topic on Absolute Value Translations to cover. 

Sections Covered in Textbook:

This is a summary of Chapter 6 so far....

Resources & Tutorials: