If I have $\displaystyle \int (x-1) e^\frac{-x}{2}$ and am integrating by parts can I have x-1 = u and $\displaystyle e^\frac{-x}{2}$ = dv

or should I multiply through the x-1 so that I am integrating this -

$\displaystyle \int x e^\frac{-x}{2} - \int e^\frac{-x}{2}$

Does it matter?