SOLUTION: x2+y2=25 xy=12

Question 92382: x2+y2=25
xy=12
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
x2+y2=25
xy=12
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Solve the 2nd equation for y and substitute into the 1st equation.
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y = 12/x
x^2+(12/x)^2 = 25
x^2 + 144/x^2 = 25
Multiply thru by x^2 to get:
x^4 + 144 = 25x^2
x^4 - 25x^2 +144 = 0
(x^2-9)(x^2-16)=0
x = 3 or x=4 or x = -3 or x= -4
correspondingly:
y= 4 or y=3 or y= -4 or y=-3
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Cheers,
Stan H.
================
Cheers,
Stan H.
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