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 —
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,
|