SOLUTION: Express the sum using summation notation. 15+13+11+...+(-43)

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Question 1059601: Express the sum using summation notation. 15+13+11+...+(-43)
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
First find the term,
A%5Bn%5D=15%2B%28n-1%29%28-2%29=15-2n=17-2n
and
17-2n=-43
-2n=-60
n=30
So,
S%5B30%5D=sum%28%2817-2i%29%2Cni=1%2C30%29