\ \
The geometric sequence is . \ \
Rewrite the sequence as . \ \
The geometirc sequence is in the form of . \ \
The first term of the sequence is . \ \
Common ratio is . \ \
Sum of the first terms of the geometric series
. \ \
Where is the first term and
is the common ratio. \ \
Substitute and
in
. \ \
\ \
The sum of the first terms of the series is
. \ \