Question

Please Please PLEASE HELP ME

What is the sum of this geometric series?

Answer 1

do you know the sum formula ?

Answer 2

Sort of D:

Answer 3

what is it ?

Answer 4

an=a1 r^(n-1)

Answer 5

thats the n'th term formula, not sum

Answer 6

\(\Large S_n = a_1 \dfrac{r^n-1}{r-1}\)

Answer 7

you'll need 3 things

a1 = 1st term =...
r = common ratio = ...
n = number of terms =...

can you tell me these 3 things ?

Answer 8

okay D:

Answer 9

1=8 2=r 3=1??

Answer 10

you mean 1st term = 1
and number of terms = 8
right ?

Answer 11

I Got it 510

Answer 12

common ratio = 2 is correct :)

Answer 13

510 is correct! :)