I need to prove from the definition of defferntiability that the function

f(x)= 2x-1/x-2

is differentiable at the point 1 and find f'(1)

So far I have

The difference quotient for f at 1 is

Q(h) = f(h)-f(1)/h

= 2h-1/h-2 + 1 / h

= ?

can anyone help?