Question

What is the sum of the geometric sequence 2, 10, 50, … if there are 8 terms?

Answer 1

The sum for a geometric sequence of the form
\[a_n=a_1r^{n-1}\]is given by the formula with n terms
\[S_n=a_1\left( \frac{1-r^n}{1-r} \right)\]
in your problem\[a_1=2\]\[r=5\]
and you said 8 terms so
\[n=8\]
substitute and keep your order of operations correct.
good luck

Answer 2

your answer should be of the form\[S_n=\]
will be equal to a value.

Answer 3

I got the answer 195,312! Thank you so much for the help and showing me how to do it.