Rational Expressions (Simplify, Multiply, Divide)

A rational expression is a fraction where the numerator and/or denominator are polynomials: [formula] The rules are the same as for numeric fractions — you can simplify by canceling common factors (not common terms!).

Steps: 1. Factor the numerator completely 2. Factor the denominator completely 3. Cancel any factors that appear in both Critical rule: you can only cancel factors (things being multiplied), never terms (things being added/subtracted).

Example: Simplify frac{x^2 - 9}{x + 3}