Question 877259: The sum of 3 numbers in arithmetic progression is 18,the sum of their squares is 206.find the numbers
Answer by richwmiller(17219)   (Show Source):
You can put this solution on YOUR website! a+a+d+a+d+d=18
3a+3d=18
a+d=6,
a^2+(a+d)^2+(a+d+d)^2=206
a^2+6^2+(6+d)^2=206
a^2+36+36+12d+d^2=206
a^2+72+12d+d^2=206
a^2+12d+d^2=134,
a+d=6
a = -1, d = 7
a = 13, d = -7
-1,6, 13
or
13,6,-1
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