SOLUTION: Find the five numbers in A.P Whoes sum is 55 and sum of whoes square is 765?

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Question 1025992: Find the five numbers in A.P Whoes sum is 55 and sum of whoes square is 765?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!

5a%5Bn%5D%2B10d=55
a%5Bn%5D%2B2d=11
a%5Bn%5D=11-2d
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Substituting from above,

+%2811-2d%29%5E2%2B%2811-d%29%5E2%2B%2811%29%5E2%2B%2811%2Bd%29%5E2%2B%2811%2B2d%29%5E2=765

+10d%5E2%2B605=765
10d%5E2=160
d%5E2=16
d=0+%2B-+4
If d=-4, then a%5Bn%5D=11-2%28-4%29=11%2B8=19
which leads to {19,15,11,7,3}
If d=4, then a%5Bn%5D=11-2%284%29=11-8=3
which leads to {3,7,11,15,19}