\"\"

\

The sum of a geometric series is \"\".

\

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

\

\"\"               (Substitute \"\")

\

\"\"               (Subtract: \"\")\"\"

\

Evaluate powers: \"\".

\

\"\"

\

\"\"              (Subtract: \"\")

\

\"\"        (Multiply by \"\", and reciprocal of \"\")

\

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

\

The value of \"\".