I have the following problem that needs to be simplified. I already have the simplification results, but I don't understand how they got it. For example, how does there and up being 2 h's, when there is only a single h to begin with. Any help on how to simplify this problem one step at a time would be appreciated.

Step 1: $\displaystyle ((3-4(-2+h)^2)-(3-4(-2)^2) / h)$

Step 2: $\displaystyle ((16h-4h^2) / h)$

Step 3:$\displaystyle (16-4h)$