SOLUTION: 5) if (x-y)^2=40 and x^2+y^2=60, then xy=?

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Question 772626: 5) if (x-y)^2=40 and x^2+y^2=60, then xy=?
Answer by reviewermath(1029) About Me  (Show Source):
You can put this solution on YOUR website!
Q:
If %28x-y%29%5E2=40 and x^2+y^2=60, then xy=?
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A:
%28x-y%29%5E2+=+x%5E2+-+2xy+%2B+y%5E2
%28x-y%29%5E2+=+%28x%5E2+%2B+y%5E2%29+-+2xy
40+=+60+-+2xy
xy+=+%2860+-+40%29%2F2+=+highlight%2810%29
Answer: highlight%2810%29