Answer
$\frac{-2x-h}{(x+h)^2x^2}$
Work Step by Step
$\dfrac{\frac{1}{(x+h)^2}-\frac{1}{x^2}}{h}=\dfrac{\frac{x^2}{(x+h)^2x^2}-\frac{(x+h)^2}{x^2(x+h)^2}}{h}=\dfrac{\frac{x^2-(x+h)^2}{(x+h)^2x^2}}{h}=\frac{x^2-(x^2+2xh+h^2)}{h(x+h)^2x^2}=\frac{-2xh-h^2}{h(x+h)^2x^2}=\frac{-2x-h}{(x+h)^2x^2}$
