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What is the sum of the first 7 terms of the series −4+8−16+32−... ?

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User Geoherna
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1 Answer

6 votes

we have that

−4+8−16+32−.....

a1=-2*(-2)-----> -4

a2=-4*(-2)-----> +8

a3=+8*(-2)-----> -16

a4=-16*(-2)----> +32

a5=+32*(-2)----> -64

a6=-64*(-2)-----> +128

a7=+128*(-2)-----> -256

The sum of the first 7 terms of the series is

[a1+a2+a3+a4+a5+a6+a7]-----> [-4+8-16+32-64+128-256]-------> -172


the answer is -172
User Linus Caldwell
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