Geometric Series Formula Quizmaster : MATHguide
Geometric Series Quizmaster: MATHguide
Review the Lesson | MATHguide homepage Updated December 4th, 2016

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Use the first 7 terms of the following geometric series for the problem below:

-20 + 40 - 80 + 160 + ...

What is the value of the common ratio? r =
What is the sum of the first 7 terms?
(to the nearest tenth) 		S7 =