Geometric Series Quizmaster: Compliments of MATHguide
Review the Lesson | MATHguide homepage Updated February 12th, 2006

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Use the first 13 terms of the following geometric series for the problem below:

-18, 36, -72, 144, ...

What is the value of the common ratio ? r =
What is the sum of the first 13 terms? S13 =