The given expression is
.
Find the terms by replacing n with 1, 2, 3, 4, and 5.
\Substitute n values in
.



The sum of an arithmetic series
.
Where
is the first term and
is the nth term.
There are 5 terms,
and
.
The fifth term of the arithmetic sequence 
(Substitute
)
(Subtract:
)
(Multiply:
)
(Divide:
)
The sum of the arithmetic series is
.