In order to subtract the two functions they must first have the same denominator.
If you multiply 4/(x-3) by x+2 you should get (4x+8) / (x^2-x-6)'
Then multiply 1/(x+2) by x-3 and your answer should be (x-3) / (x^2-6).
You then combine the numerator by like terms all over the denominator. It should look like (4x-x+8-(-3) / (x^2-x-6)
4x - x = 3x and 8 - (-3) = 11 (Using skip change change)