$\"\"$

The expression is $\"\"$ .

Rewrite the expression $\"\"$ .

So, the first term is $\"\"$ , the common ratio $\"\"$ .

The infinite geomentric series is $\"\"$ .

$\"\"$ ( Substitute $\"\"$ and $\"\"$ )

The formula is $\"\"$ .

$\"\"$ $\"\"$

The solution is $\"\"$ .