WTAMU > Virtual Math Lab > College Algebra > Tutorial 9: Multiplying and Dividing Rational Expressions
 Answer/Discussion
to 1a
|
| Step 1: Factor both the
numerator and the denominator
AND |
| Step 2: Write as one
fraction. |
| Step 3: Simplify the
rational expression.
AND |
| Step 4: Multiply any
remaining factors in the numerator and/or denominator. |
 |
*Simplify
by div. out the common factors of
x, (x
- 1) and (x + 1)
*Multiply
the den. out
*Excluded values of the original den. |
| Note that the values that would be excluded from the domain are
0, -5, -1, and 1. Those are the values that makes the original
denominator equal to 0. |
| Answer/Discussion
to 1b
|
 |
*Rewrite as mult. of reciprocal
*Factor
the num. and den.
*Simplify
by div. out the common factors of
3, (y^2 + 4),
(y - 5), and (y
+ 2)
*Multiply
the den. out
*Excluded values of the original den. of product |
| Note that even though all of the factors in the numerator were divided
out there is still a 1 in there. It is easy to think there there
is "nothing" left and make the numerator disappear. But when you
divide a factor by itself there is actually a 1 there. Just like
2/2 = 1 or 5/5 = 1.
Note that the values that would be excluded from the domain are 0,
5, -2, and 2. Those are the values that makes the original
denominator of the product equal to 0. |
WTAMU > Virtual Math Lab > College Algebra > Tutorial 9: Multiplying and Dividing Rational Expressions
All contents copyright (C) 2002 - 2008, WTAMU and Kim Seward. All rights reserved.
Last revised on Feb. 29, 2008 by Kim Seward.
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