Question

What is the sum of the geometric sequence -3,18,-108,..if there are 8 terms?

Answer 1

can u help me?

Answer 2

Geometric Sums formula:
\[S_{n} = \frac{ a_{1} (1-r^n) }{ 1-r }\]

Answer 3

so s=-3(1-(-6)^8)/1-(-6)?

Answer 4

Definitely! :)

Answer 5

ty