226k views
3 votes
Find the sum of the geometric series given a1=2, r=−3, and n=8.

User Gfrobenius
by
8.1k points

1 Answer

3 votes

Answer:

S₈ = - 3280

Explanation:

The sum to n terms of a geometric series is


S_(n) =
\frac{a_{}(r^(n)-1) }{r-1}

Here a₁ = 2, r = - 3 and n = 8 , then

S₈ =
(2((-3)^(8)-1) )/(-3-1)

=
(2(6561-1))/(-4)

=
(2(6560))/(-4)

=
(13120)/(-4)

= - 3280

User Mik
by
7.9k points

No related questions found

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

9.4m questions

12.2m answers

Categories