SOLUTION: Find the sum indicated for each of the geometric series listed. -16 - 8 - 4 - ..., find S8

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Question 412082: Find the sum indicated for each of the geometric series listed.
-16 - 8 - 4 - ..., find S8
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

Geometric Series: {-16,-8,-4 ...} r = .5  

sum%28+a%5Bi%5D%2C+i=1%2C+8+%29 = a(1-r^8)/(1-r)

sum%28+a%5Bi%5D%2C+i=1%2C+8+%29 = -16(1-.5^8)/.5 = -16*.99609375/.5 = -31.875