the sum of the first n terms of an ap is given by SN = 2n^2 + 3n find the 16th term of the AP
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You know that Sn = 2n^2 + 3n. So find the first term of the ap that is a1 by substituting n=1 in the gn equation(S1=a1). Also find the 2nd term which is S2 - S1( substitute n=2 in the equation and subtract this value from the value that you got while substituting n=1). As u got a1 and A2, now find d by subtracting a1 from A2. Now as you know a, d and 1 you can find a16 which a+15d. If you do so, I think the answer would be 140. Check it.
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