SOLUTION: Let x = 2012(a - b), y = 2012(b - c), and z = 2012(c - a), where a,b,c are real numbers, and assume
xy + yz + zx is not = 0. Compute (x^2 + y^2 + z^2)/(xy + yz + zx).
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-> SOLUTION: Let x = 2012(a - b), y = 2012(b - c), and z = 2012(c - a), where a,b,c are real numbers, and assume
xy + yz + zx is not = 0. Compute (x^2 + y^2 + z^2)/(xy + yz + zx).
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Question 1078282: Let x = 2012(a - b), y = 2012(b - c), and z = 2012(c - a), where a,b,c are real numbers, and assume
xy + yz + zx is not = 0. Compute (x^2 + y^2 + z^2)/(xy + yz + zx). Found 2 solutions by Edwin McCravy, ikleyn:Answer by Edwin McCravy(20064) (Show Source):
You can put this solution on YOUR website! Let x = 2012(a - b), y = 2012(b - c), and z = 2012(c - a), where a,b,c are real numbers, and assume
xy + yz + zx is not = 0. Compute (x^2 + y^2 + z^2)/(xy + yz + zx).
The 2012 was just put in there to complicate matters. It could
have been any number whatever. Most likely this problem was made
up 5 years ago in in 2012. Let's just divide everything through
by 2012:
, , and
Add all those equations together:
Multiply thru by 2012:
So
We want to compute:
Substitute -x-y for z
Edwin
You can put this solution on YOUR website! .
Let x = 2012(a - b), y = 2012(b - c), and z = 2012(c - a), where a,b,c are real numbers, and assume
xy + yz + zx is not = 0. Compute (x^2 + y^2 + z^2)/(xy + yz + zx).
~~~~~~~~~~~~~~~~~~~~~
It could be done shorter.
x = 2012(a - b), y = 2012(b - c), and z = 2012(c - a) ===>
x + y + z = 2012*(a-b+b-c+c-a) = 0.
Hence
0 = = = + ===>
= ===>
= -2.