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What is the sum of the infinite geometric series? −5+2−4/5+8/25−16/125...

1 Answer

8 votes

Answer:

-25/7

Explanation:

The sum of an infinite series with first term 'a' and common ratio 'r' is ...

S = a/(1 -r)

Your series has a=-5 and r=-2/5, so the sum is ...

S = (-5)/(1 -(-2/5)) = -5/(7/5) = -25/7

The sum of the series is -25/7.

User Scott Ridings
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