The sum of first 7terms of is 63and sum of next 7terms is161 find the

1.	The sum of first 7terms of is 63and sum of next 7terms is161 find the 28thTerminal of AP
Answer» sum of 1st 7 terms = 63sum of 1st 14 terms = 63 + 161 = 224let 1st term = acommon difference = ds7 = 7/2(2a + 6d) = 63 .... is14 = 14/2 (2a + 13d) = 224 .... iifrom i and ii7a + 21d = 63a + 3d = 9a = 9 - 3d putting the value a in ii2a + 13d = 3218 - 6d + 13d = 327d = 14d = 2\xa0a = 9 - 6a = 3a28 = a + 27d = 3 + 54 = 57

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