# Determine whether the geometric series is convergent or divergent. 10-4+1.6-0.64+... If it convergent, find the sum.

Series
Determine whether the geometric series is convergent or divergent.
$$10-4+1.6-0.64+...$$
If it convergent, find the sum.

$$a=10$$
$$r=\frac{-4}{10}=\frac{-2}{5}$$
$$S_n=\frac{a}{1-r}$$
$$=\frac{10}{(1+\frac{2}{5})}$$
$$=\frac{50}{7}$$