Question

find the sum to the required number of terms for the geometric series

1-5+25-125...to 6 terms

Answer 1

do you know formulas?

Answer 2

here b1=1 and q=-5

Answer 3

you need to find sum of them all till n=6

Answer 4

s=b1*(1-q^n)/(1-q)

Answer 5

substitute numbers and you will get the answer

Answer 6

i got 15625/6

Answer 7

is it ok to get like a decimal

Answer 8

no

Answer 9

i got 2604

Answer 10

check again, you missed here (1-q^n)

Answer 11

don't forget 1

Answer 12

after plugging in, it would be 1(1-(-5)^6) / 1-(-5)
1(1-15625)/ 6
-2604

Answer 13

is that right?

Answer 14

yes

Answer 15

ok thank you !