I have two questions, both of which I am stuck on:

Problem #1:

Instructions state, 'Simplify the expression:'

y - x / (x^2 + xy - 2y^2)

Problem #2:

Instructions state, 'Perform the indicated operation and simplify if possible:'

3 / (x^2 - 9) + 2 / (x - 3)

I've determined that x^2 - 9 can be factored to (x + 3) (x - 3) but I don't know where to take it from here. Do I have to find an LCD to solve this?