# Multiplying Rational Expressions

You probably know how to multiply rational expressions that contain monomials. Now, we will use the same procedure to multiply rational expressions that contain binomials or trinomials.

Note:

Here is an example of multiplying rational expressions that contain monomials:

Procedure â€” To Multiply Rational Expressions

Step 1 Factor the numerators and denominators.

Step 2 Cancel all pairs of factors common to the numerators and denominators.

Step 3 Multiply the numerators. Multiply the denominators.

We usually leave the answer in factored form.

Example 1

Find:

 Solution Step 1 Factor the numerators and denominators. Step 2 Cancel all pairs of factors common to the numerators and denominators. Step 3 Multiply the numerators, and then multiply the denominators.

Thus,

Example 2

Find:

 Solution Step 1 Factor the numerators and denominators. Step 2 Cancel all pairs of factors common to the numerators and denominators. Replace with -1. Step 3 Multiply the numerators, and then multiply the denominators.

So,