# What is the sum of the geometric sequence -4,24,-144,... if there are 8 terms?

##### 1 Answer

May 17, 2018

#### Explanation:

Sum of geometric sequence is

where

a = your first number

r = the ratio

n = number of terms

In this case,

a = -4

r =

n = 8

Sum

=

=

=

=

=