Can somebody please help me out with this?

Let $\displaystyle f(x)=(2/x)-4$, then the expression

$\displaystyle [f(x+h)-f(x)]/h$ can be written in the form

$\displaystyle (A)/(Bx^2+Cxh)$, where A, B, and C are constants.

Find A, B, and C.

Any help would be greatly appreciated. Thanks!