Question

PLEASE HELP ASAP!!! CORRECT ANSWER ONLY PLEASE!!!

What is the sum of the series?

4 + 12 + 36 + 108 + ... + 8748

Answer 1

Answer: (C) 13,120

Explanation:

Given the sequence {4, 12, 36, 108, ... , 8748} we know that the first term (a) is 4 and the ratio (r) is
`(12)/(4)=3`

Input the values above into the Sum formula:

`S_n=(a(1-r^n))/(1-r)\\\\S_8=(4(1-3^8))/(1-3)\\\\.\quad=(4(1-6561))/(-2)\\\\.\quad=(4(-6560))/(-2)\\\\.\quad=-2(-6560)\\\\.\quad=13,120`