- #1

MillerGenuine

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## Homework Statement

[tex] \sum_{n=1}^\infty \frac{(-3)^{n-1}}{4^n} [/tex]

## The Attempt at a Solution

[tex] \sum_{n=1}^\infty \frac{(-3)^n-1}{4^n} [/tex]

[tex] \frac{1}{4}\sum_{n=1}^\infty \frac(-{3}{4})^{n-1} [/tex]

Can some one please explain how they got from the first step to the 2nd. How do you pull out a 1/4 and how does the "n" on the 4 dissapear?

Thanks