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June 13th, 2018, 08:08 AM   #1
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Solve This Equation For xy

3x^2 + xy = 2y^2

Can you solve for xy?
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June 13th, 2018, 09:37 AM   #2
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Hi EvanJ.

$$3x^2 + xy = 2y^2$$


$$(3x-2y)(x+y)=0\implies 3x=2y,x=-y$$



Now sub into the original equation and take it from there.
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June 13th, 2018, 10:25 AM   #3
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Using quadratic:

solve for x : x = -y or x = 2y/3

solve for y : y = -x or y = 3x/2

Just trying to cause confusion
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June 13th, 2018, 04:48 PM   #4
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Originally Posted by greg1313 View Post
$$(3x-2y)(x+y)=0\implies 3x=2y,x=-y$$
The left hand equation doesn't imply that both right hand equations hold.
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