#### Answer

See below.

#### Work Step by Step

The sum of the first $n$ terms of the sequence can be obtained by the formula $S_n=(a_1+a_n)\frac{n}{2}$ where $a_1$ is the first and $a_n$ is the last term.

Chegg costs money, GradeSaver solutions are free!

Published by
Pearson

ISBN 10:
0-13417-894-7

ISBN 13:
978-0-13417-894-3

See below.

You can help us out by revising, improving and updating this answer.

Update this answerAfter you claim an answer you’ll have **24 hours** to send in a draft. An editor
will review the submission and either publish your submission or provide feedback.