Do you mean to edit the formulas once copied? Sure. Either double-click the cell and edit the formula there or select the cell and edit it in the formula bar.

May I ask why you need to edit it? It may be just that you need to properly reference cells in your formula prior to copy/paste.

For example, if your formula refers to A1 and you copy it down, Excel will automatically refer the next cell down to A2. However, if you want the formula to always refer to A1, all you need to do is put a $ in front of the 1 in A1 in the first formula i.e. A$1.

Similarly for copying across. if you want to hold the referred cells column, put a $ in front of the A i.e. $A1. Finally, if you want it held to A1 in either direction - up, down, left, right - put a $ in front of both i.e. $A$1.