Question

What is the sum of a 7-term geometric series if the first term is 6, the last term is 24,576, and the common ratio is -4?

-32,766
-19,662
19,662
32,766

Answer 1

@dan815

Answer 2

@Preetha

Answer 3

@pooja195

Answer 4

@welshfella

Answer 5

@welshfella

Answer 6

i WILL MEDAL/FAN PLEASE HELP!

Answer 7

\[\sum_{i=1}^{n}a _{i} = a _{1}\frac{ 1-r ^{n} }{1-r }\]

Answer 8

I dont understand the formula

Answer 9

just plug the values in the RHS and you'll get the sum

Answer 10

a1=6, r=-4 and n=7

Answer 11

What values?

Answer 12

Oh okay

Answer 13

I got 19,664.4

Answer 14

ans is -19662

Answer 15

How did u get that?

Answer 16

@AHSHAJHASJDHS ur ans is wrong,,,,according to me...

Answer 17

no your both wrong

Answer 18

ok wait i am expplaining

Answer 19

Can you help me get to the right answer? Mine didnt even match

Answer 20

\[6 \frac{ 1-(-4)^{7} }{1-(-4)}\]

Answer 21

this is what you need to calculate

Answer 22

I got 19,662

Answer 23

(6) 16385
------- = 3277 (6) = 19662
5

Answer 24

Is that right?

Answer 25

Yep, thats it