Topic: Rational Expressions
Subtopic: Operations II - Multiply & Divide
Overview
When multiplying fractions in arithmetic you reduce each fraction, cross cancel to simplify, then multiply. Similarly when multiplying algebraic rational expressions, you factor every numerator and denominator completely, reduce each fractions, cross cancel like factors, then multiply. Dividing two rational expressions is similar except that you flip the second fraction to convert to multiplication first.
Objectives
By the end of this topic you should know and be prepared to be tested on:
- 8.2.1 Multiply two or more rational expressions factoring, reducing, and cross cancelling to simplify as needed
- 8.2.2 Divide two rational expressions by "flip and multiply"
Terminology
Define: reduce, cross-cancel, reciprocate (a.k.a. flip)
Text Notes
Text:
Intro & Inter Algebra for CS 3ed by Blitzer, sect. 7.2
- Pay special attention to the examples that contain "opposites". Watch your signs! There is lots of factoring throughout this section. Factor carefully!