Question

I did multiply for by 4 and added them but didn't get the right answer.. please help! medal for correct answer!

What is the sum of the first seven terms of the geometric series?

3 + 12 + 48 + 192 + ...

Answer 1

@Easyaspi314

Answer 2

a1(1 - r^n)/(1-r) is the formula for the sum of the first n terms of a geometric series

Answer 3

The answer would be 12,288?

Answer 4

a1 = first term = 3; r = 4

so you get...[3(1-4^(7)]/(1-3)

Answer 5

divided by (1-4), not (1-3) r = 4

Answer 6

-49161?

Answer 7

I believe that is 16,383

Answer 8

It is -49161/-3 = 16,383

Answer 9

Oh, it is! I see what you're talking about now. Awesome.

Answer 10

@mathgeek0912 Welcome.