find the sum of the geometric series -3,15,-75,375 when there are 9 terms and select the correct answer below

asked Nov 25, 2017 61.8k views

1 vote

6.9k points

Please log in or register to add a comment.

3 votes

The sum to nterms:

Sn=a(r^n - 1) / (r-1)

r=15/-3=-5
a=-3

Sn=-3(-5⁹ - 1) / (-5-1)=-976563

Answer; -976563

Tammye answered Dec 2, 2017

7.3k points

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

8.5m questions

11.2m answers