Question

How would I multiply the following rational expression?

((a-b) (a+b))/((a^2-b^2))/((b)/(a+b))

Answer 1

focus on each individual variable, so look at the numerator first:
(a-b)(a+b). focus on the first parentheses and multiply each term into the next parentheses.

a* a = a^2
a*b = ab
then focus on the second term in the first parentheses
-b*a = -ab
-b*b = -b^2
combine all of them
a^2 + ab - ab - b^2
the ab's cancel out
a^2 -b^2 on the numerator

that crosses out the dividing term under that to become one over b over a+b...i think. can you draw out your question?