Infinite geometric series problem

[MillerGenuine]

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

 

[Mark44]

Can you fix your third summation? It's all fouled up.