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Sum of first n terms is 3n2 + n. Find the 22nd Term. |
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Answer» Sn = 3n2 + n S22 = 3(22)2 + 22 S22 = 1452 + 22 ∴ S22 = 1474 S21 = 3(21)2 + 21 S21 = 1344 a22 = S22 - S21 ∴ a22 = 1474 - 1344 ∴ a22 = 130 Hence, the 22nd term of A.P is 130 |
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