Question

Anyone help me please?

What is the sum of an 8-term geometric series if the first term is 15 and the last term is -4,199,040?

Answer 1

i really need help? can you

Answer 2

The nth term of a geomtric sequence is given by:
\[a _{n} = a _{0}r ^{n - 1}\]
You know a0 and a8. First find r

Then the sum is:
\[S = a _{0}(\frac{ 1 - r ^{n} }{ 1 - r })\]

Answer 3

i dont know how to follow this..

Answer 4

Let's start with the first part. You need to find r