find four numbers in AP whose sum is 20 and sum of whose squares is 120

Asked by sonaisha | 9th Mar, 2009, 06:28: PM

Expert Answer:

four numbers in A.P. be a-3d,a-d,a+d,a+3d..(imp step) Acc to question, a-3d+a-d+a+d+a+3d=20 So, 4a=20 a=5 Next,  sum of the squares of these numbers =120 (given) So, the A.P. is 2,4,6,8 (with d=1) or 8,6,4,2 (with d=-1)  

Aswered by  | 10th Mar, 2009, 12:04: PM

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