$\"\"$

The given values $\"\"$ .

Apply alternative formula for sum of a geometric series $\"\"$ .

Where $\"\"$ is first term and r is common ratio.

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

$\"\"$ (Product of two same signs is positive) $\"\"$

$\"\"$ (Subtract denominator: $\"\"$ )

$\"\"$ (Multiply: $\"\"$ )

$\"\"$ (Add: $\"\"$ )

$\"\"$ (Divide: $\"\"$ ) $\"\"$

The value of $\"\"$ .