Answer
This series diverges.
Work Step by Step
To determine whether or not this series converges or diverges, we need to find the common ratio, $r$. This can be done by setting up a ratio of the second term to the first term:
$r = \frac{-20}{-10} = 2$
When $|r| \lt 1$, then the series converges; when $|r| \gt 1$, then the series diverges. Since $|r| \gt 1$ in this case, this series diverges.
