Question

The first term of a geometric series is -3, the common ratio is 6, and the sum of the series is -4,665 Using a table of values, how many terms are in this geometric series

Answer 1

5

Explanation:

Answer 2

There are 5 terms in the series.

Explanation:

`S=a(1-r^(n) )/(1-r)\\a=-3\\r=6\\-4665=-3(1-6^(n) )/(1-6)\\1555=(1-6^(n) )/(-5)\\\-7775=1-6^(n)\\6^(n)=7776\\`

Take logs to get n = 5