I hope this belongs here, But I have no idea where to start on an equation like this where you are dividing something that is already being divided.

Simplify as much as possible.

f(x)=1/x(f(a+h)-f(a))/h

So i get

(1/(a+h)) - (1/a) / h

then im stuck. I knink this should be really easy but like i said dividing by something that is already getting divided.... if anyone has a set of rules that can be applied to something like this please let me know.