SOLUTION: One pair of integers (x.y) solves {{{ sqrt( 4*sqrt( 7 )+11 )=y+sqrt( x ) }}}, find x*y.

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Question 1107093: One pair of integers (x.y) solves +sqrt%28+4%2Asqrt%28+7+%29%2B11+%29=y%2Bsqrt%28+x+%29+, find x*y.
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
+sqrt%28+4%2Asqrt%28+7+%29%2B11+%29=y%2Bsqrt%28+x+%29+

square both sides:

+4%2Asqrt%28+7+%29%2B11+=%28y%2Bsqrt%28+x+%29%29%5E2+

+4%2Asqrt%28+7+%29%2B11+=y%5E2%2B2y%2Asqrt%28+x+%29%2Bx+

Since x and y are integers we can set the integer terms
on the left equal to the integer terms on the right

11+=y%5E2%2Bx+

and we can set the irrational terms on the left equal to the
irrational terms n the right:


+4%2Asqrt%28+7+%29+=2y%2Asqrt%28+x+%29+

It's quite obvious that to have integer solutions
x must be 7, and y must be 2.

We see if that checks in

11+=y%5E2%2Bx+
11+=2%5E2%2B7+
11+=4%2B7+
11+=11+

Yes it does, so x*y = 7*2 = 14

Edwin