I am having a hard time with this, I am not sure if its just the sheer size or something in my calculations. I am grateful to anyone who wants to take this on:

4a^2-20a/a^2+2a-35 + 3a-6/3a^2-10a+8

So far all I have is the simplified version of the two denominators

(a+7)(a-5) (3a-4)(a-2)

Then after this the equation is too huge for me to deal, with it seems.