Question

What is the sum of the geometric sequence 8, –16, 32 … if there are 15 terms?

Answer 1

Answer:

87384

Step-by-step explanation:

a=2,r=-2,n=15

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

=8*[(-2)^15-1]/[-2-1]

=-8/3*(-32768-1)

=-8/3(-32769)

=262152/3

=87384