Question 1026099
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Write the sum using summation notation, assuming the suggested pattern continues.

8 - 40 + 200 - 1000 + ... 
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8 - 40 + 200 - 1000 + ... = {{{ sum (8*(-5)^k , k=0, n-1 ) }}}.


This is the sum of the first n terms of a geometric progression with the first term 8 and the common ratio (-5).

This sum is finite.


It can not be infinite since this series is divergent.


On geometricic progressions see the lesson <A HREF=https://www.algebra.com/algebra/homework/Sequences-and-series/Geometric-progressions.lesson>Geometric progressions</A> in this site, and the lessons associated with it.
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