Manipulation of Absolutely Convergent Series/Scale Factor

Theorem
Let $\displaystyle \sum_{n \mathop = 1}^\infty a_n$ be a real or complex series that is absolutely convergent.

Let $c \in \R$, or $c \in \C$.

Then:


 * $\displaystyle c \sum_{n \mathop = 1}^\infty a_n = \sum_{n \mathop = 1}^\infty c a_n$