Find the sum of first 22 terms of the AP 8,3,-2,....

1.	Find the sum of first 22 terms of the AP 8,3,-2,....
Answer» A = 8 ,, d = 3 - 8 = - 5 ,,S22 = 22 / 2 [ 2 ( 8 ) + ( 22 - 1 ) - 5 ,,S22 = 11 [ 16 + 21 × - 5 ] ,,S22 = 11 [ 16 + ( - 105 ) ] ,,,,S22 = 11 [ - 121 ] ,,S22 = - 1331 .= - 1331 . Thank you. \xa0a=8d=3−8=−5S22\u200b=n/2\u200b[2a+(n−1)d]S22\u200b=22/2\u200b[2a+21d]S22\u200b=11[2(8)+21(−5)]S22\u200b=11(−89)=−979.

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