Is anyone up for helping me out with a bit of homework?

Pretty please???

I've got 3 differentiation questions and 3 simultaneous equations, and I just can't get my head round them. I've tried for 2 weeks now, and I just can't do it. I feel sick to the stomach for having to ask, but I'll mess up a whole years course if I can't do them. Here goes.................

Find dy/dx for:

A. y = x(cubed) - x(squared)

B. y = (x-1) (x+2)

Find the turning points for the following and state what type of turning points they are:

C. y = x(cubed) - 3x + 2

Solve for x and y:

D. 17x + 9y = 20, 5x - 2y = -22

E. x = 2y, x(squared) + 3xy = 10

F. y - x = 2, 2x(squared) + 3xy = y(squared) = 8

I'm doing a psychology course (believe it or not), so if anyone needs any help with that sort of stuff, I'm more than happy to help.

Thanks