difference quotient help please!! =O

okay, so I'm working on my homework and I am completely lost on this one problem for some reason, if someone could show me how to start it that would be amazing!! (I am also going to post how I think its started so if I am wrong please tell me and if I'm right point me in the right direction?)

Okay so the problem im having trouble with is

"suppose f(x)=2x^2+3x+1. Simplify the difference quotient: f(A+h)-f(A)/h"

How I think its started is [2(x+h)^2+(x+h)+1]-(2x^2+3x+1)/h but im not sure if I am totally off base here...

Please please please help, it's due tomorrow and like I said im lost

Wait, never mind, I think I got it. Tell me if I'm wrong of course =)

2(A+h)(A+h)+3A+3h+1-2A^2-3A-1/h = 4Ah+2h^2+3h/h = 4A+2h+3

I think its right but if anyone more math savvy can see a problem please lemme know =)

Yes, that is indeed what I got. Well done.
Remember: Expand, cancel, factor by h.