What is the sum of a 7-term geometric series if the first term is - 11, the last term is - 171,875, and the common ratio is - 5? - 143,231 - 36,047 144,177 716,144

The answer is - 143,231.

The first step to solving this problem is to find all terms in the sequence. Since this is a geometric sequence, the next term can be found by multiplying the current term by the common ratio.

That means that the second term can be found by: - 11*-5 = 55

And the third term can be found by 55*-5 = - 275

And so on ...

Here are all seven terms:

-11, 55, - 275, 1375, - 6875, 34375, - 171,875

The next step is to add them all up to find the sum which end up as - 143,231, which is your final answer.