Section 7-2
Multiplying and Dividing Rational Expressions
MULTIPLYING RATIONAL EXPRESSIONS
To multiply two rational expressions, just multiply the numerator and denominator
separately (as you would with fractions), and then simplify the result if possible.
It's often easier if you factor the numerators and denominators before multiplying
them, rather than after.
Example:
Multiply.
Factor first.
Now multiply.
Factor out an x + 2 and a 3 from both numerator and denominator.
= 2x(x – 2)
Note that –2 is an EXCLUDED VALUE.
DIVIDING RATIONAL EXPRESSIONS
This is easy. How do you divide fractions? By flippling the divisor over,
and then multiplying, right?
Same thing with rational expressions.
Example:
Divide.
Invert and multiply.
You could try factoring first, but in this case, there are no common factors.
