SOLUTION: The sum of the eleven terms of AP is 286.If the eleventh term is 46.find the first term.

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Question 1012531: The sum of the eleven terms of AP is 286.If the eleventh term is 46.find the first term.
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
The sum of an arithmetic progression is found by
S = n(a1 + an)/2
so that
286 = 11(a1 + 46)/2
572 = 11a1 + 506
66 = 11a1
a1 = 6