SOLUTION: 1) What is a possible expression for the series -6 -12 -24 -48 -96 -192 2) What is a possible expression for the series -7 +12 -17 +22 -27

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Question 1085483: 1) What is a possible expression for the series
-6 -12 -24 -48 -96 -192
2) What is a possible expression for the series
-7 +12 -17 +22 -27
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
1) What is a possible expression for the series
-6 -12 -24 -48 -96 -192
That's a geometric series with a1=-6 and common ratio =r=2
2) What is a possible expression for the series
-7 +12 -17 +22 -27
That would be an arithmetic series with a1=-7 and common 
difference = d = 5 if it weren't for the alternating signs.  So we
use the arithmetic series formula and multiply by the sign changing
factor (-1)n



Edwin