### Math Notes

Subjects

#### Algebra Solutions

##### Topics || Problems

What is the sum of the infinite geometric series of 1, -1/5, 1/25, ...?
Solution

$$r = \frac{-1/5}{1} = \frac{-1}{5}$$

$$S_g = \frac{a_1}{1-r}$$

$$S_g = \frac{1}{1+1/5}$$

$$S_g = \frac{5}{6}$$