If the sum of n terms of an AP be 3n square +n and its common difference is 6, then find its first term.

Asked by snehamapink | 13th Feb, 2012, 04:35: PM

Expert Answer:

S= 3(1)+ (1) = 4
So, first term is 4
S2  = 3(2)2 + 2 = 14
Second term is S- S1 = 14 - 4 = 10

Answered by  | 13th Feb, 2012, 11:04: PM

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