This one is simple. Distribute the negative (-) to the 1/x. The 1/x becomes negative and you can cancel the 1/x out. This leaves you with "h". Hope this helps!
\(\frac{1}{x+h}-\frac{1}{x}\) You need a common denominator. That will be x(x +h). \(\frac{x}{x(x+h)}-\frac{(x+h)}{x(x+h)} \\ \\ \frac{x-(x+h)}{x(x+h)} \\ \\ \frac{-h}{x^2+hx}\)
