Question

What is the sum of the geometric sequence –3, 18, –108, … if there are 7 terms?

Answer 1

The ratio is -6.

\(\Large \color{Black}{\Rightarrow a{1 - r^n \over 1 - r} }\)

Here is the formula.

Answer 2

Replace n with 7.

Answer 3

-119973

Answer 4

Do you have any explanation @anuragtripathi ?

Answer 5

same formulae u used

Answer 6

I'm not sure what to tell you....but umm you'll know it soon

Answer 7

is that wrong...?

Answer 8

No

Answer 9

then?

Answer 10

I don't have a right to say that. Maybe moderators will tell it you hehe

Answer 11

Yes, exactly

Answer 12

:)