ƒ(x) = 1/x+2
1. Why have you put a question about a Derivative in Pre-Calculus when it is clearly Calculus?
2. Some brackets where they're needed to avoid ambiguity would be nice. Is your function $\displaystyle \displaystyle \begin{align*} f(x) = \frac{1}{x} + 2 \end{align*}$ or $\displaystyle \displaystyle \begin{align*} f(x) = \frac{1}{x + 2} \end{align*}$?
3. Have you tried anything? Please post what you have tried and exactly where you are stuck.
brosnan123, because you have shown no attempt yourself, we have no idea what methods you can, or are allowed, to use. mpx86 indicated a method using the basic definition. But there are also many "rules", such as the "power rule" (the derivative of x^n is nx^(n-1)) that could be applied here.