posted by pop .
Perform the indicated operation and simplify?
Multiply the first fraction by the denominator of second and vie versa:
You can do a little more from here, but this exerise does not yield a very pretty answer.
Remember that (a^2)-(b^2) = (a-b)(a+b)
Minor ammendment: I see how the first sentence can be misleading. You multiply both numerator and denominator, not just the numerator.