Question

What is the sum of the geometric sequence -3, 18, -108, ... if there are 8 terms?

Answer 1

u bttr hav da answer skyz

Answer 2

>.> xD

Answer 3

xDDD

Answer 4

IM thinking and cleaning

Answer 5

am heading back soon

Answer 6

riitee >_> back? o-o back where

Answer 7

back to ow my fathers i wont b able to tc no more

Answer 8

awww dat sucks yo

Answer 9

Use the formula for the sum of a geometric sequence for n terms.

In your problem, n = 8
ratio, r = 18/-3 = -6
the first term, a, is a = -3

Now it is straightforward substitution into the formula.

Answer 10

uhhh is this the correct formula? Sn=a(1-rn)÷(1-r)

Answer 11

Im bout to get on mic as soon mom leaves so ill be on for the last time

Answer 12

ok :3 ill get on

Answer 13

good