Lesson 8.1

The Product Rule

When we multiply matching bases, we don't multiply the powers... we gather them up.

Introduction

We are entering the "Bridge" to Intermediate Algebra. This unit focuses on Exponents and Polynomials. The first rule is about what happens when you multiply two powers with the same base.

Past Knowledge

Lesson 1.4 (Exponents). You must know that .

Today's Goal

Simplify expressions like by adding the exponents.

Future Success

This is the foundation for Multiplying Polynomials (Lesson 8.6) and Scientific Notation.

Key Concepts

The Rule

If the bases are the same, ADD the exponents.

Why?

Worked Examples

Example 1: Basic Variables

Basic

Simplify:

1

Check Bases

Both are . Good.

2

Add Exponents

Answer

Example 2: Coefficients vs. Exponents

Intermediate

Simplify:

1

Multiply Numbers

Coefficients are normal numbers. Multiply them.

2

Add Powers

Exponents get added.

Answer

Example 3: Multiple Variables

Advanced

Simplify:

1

Coefficients

2

Variable A

Recall that plain is .

3

Variable B

Answer

Common Pitfalls

Multiplying Exponents

Students often multiply the exponents because they see a multiplication sign. NO! is , not .

Adding Coefficients

Students get so used to adding exponents that they add the big numbers too. is , not .

Real-Life Applications

Computer Memory:

  • Computers deal with massive numbers of bits. is a Kilobyte. is a Megabyte.
  • To calculate total memory, computer engineers strictly use exponent rules.

Practice Quiz

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