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?