MillerGenuine
- 64
- 0
Homework Statement
\sum_{n=1}^\infty \frac{(-3)^{n-1}}{4^n}
The Attempt at a Solution
\sum_{n=1}^\infty \frac{(-3)^n-1}{4^n}
\frac{1}{4}\sum_{n=1}^\infty \frac(-{3}{4})^{n-1}
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