What is the sum of the first nine terms of the geometric series where a1 = 7 and r = −3?

Question

asked Apr 7, 2017 222k views

1 Answer

Md Alamin · Answer 1 · 2017-04-12T06:17:28+0000

Sum of terms of a geometric series
Sn = a1 (r^n-1)/(r-1)
a1 = 1st term = 7
n = number of terms = 9
r = common ratio = -3

Sn = 7 ((-3)^8-1)/(-3-1) = -11480
Hence the sum is -11480.

What is the sum of the first nine terms of the geometric series where a1 = 7 and r = −3?

Please log in or register to add a comment.

Please log in or register to answer this question.

1 Answer

Please log in or register to add a comment.

No related questions found

Categories

Other Questions