- #1

- 67

- 4

## Homework Statement

Calculate ##\sum\frac{4^{n+1}}{5^n}## (where n begins at 0 and approaches infinity).

## Homework Equations

## The Attempt at a Solution

I could easily solve this if the numerator were just ##4^n## instead of ##4^{n+1}##, because then it would be a geometric series with ratio of ##\frac{4}{5}##. But I'm not sure how to approach this one. Any help would be appreciated.