Question

Find the sum of the first 5 terms of the geometric series.


8 – 16 + 32 – ...

Answer 1

The answer to 8-16+32 = 88

Answer 2

88

Explanation:

You are multiplying -2 each time to find the next term:

8 x (-2) = -16

-16 x (-2) = 32

32 x (-2) = -64

-64 x (-2) = 128

Now, find the sum of the first 5 terms:

8 - 16 + 32 - 64 + 128 = (-16 - 64) + (128 + 32 + 8) = (- 80) + (168) = 88

88 is the sum of the first 5 terms of this series.

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