Geometric Sequence

Hope someone can help me with this problem:

A geometric series has a second term of 6 and the sum of it's first three terms is -14, what would be it's fourth term?

Koogie22 said:

Hope someone can help me with this problem:

A geometric series has a second term of 6 and the sum of it's first three terms is -14, what would be it's fourth term?

Click to expand...

A long as you know what a geometric sequence (not "series") is, this is pretty straight forward, isn't it? A geometric sequence is of the form "a, ar, ar^2, ar^3, etc.". Here, you are told that ar= 6 and that a+ ar+ ar^2= -14. That gives you two equations to solve for a and r. Use r=6/a to reduce the second equation to a quadratic equation in a.

Hi koogie:

This is a tutoring website. Volunteer tutors need to know why you're stuck.

Please read the forum guidelines, before posting your reply; here's a link to the summary page.

(You'll find links to the complete rules and guidelines near the bottom.)

Thank you! :cool: