$\"\"$

The series is $\"\"$ .

Rewrite the series as $\"\"$ .

The series is $\"\"$ .

The series is in the form of geometric sum $\"\"$ .

In this case $\"\"$ and $\"\"$ .

A geometric series with common ratio $\"\"$ diverges if $\"\"$ .

If $\"\"$ , then the series is converges to the sum $\"\"$ .

$\"\"$ .

The series converges to 8.

$\"\"$

$\"\"$ is converges.