How do you find the answer to 25-13f=-14? It is a two step equation.

25 - 13f  =  -14

First step:  get the variable term, the f-term, by itself:  

Subtract 25 from both sides:

--->   -13f = -14 - 25

--->   -13f  =  -39

Second step:  divide both sides by -13:

--->   -13f / -13  =  -39 / -13

--->   f  =  3