Question 1121290: if x^3 +y^3 =37 , x^2 + y^2 = 25 Find x+y
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! if x^3 +y^3 =37 , x^2 + y^2 = 25
Find x+y
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x^3 + y^3 =37
(x+y)*(x^2 - xy + y^2) = 37
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x^2 + y^2 = 25 looks like the 3, 4, 5 triangle.
3^2 + 4^2 = 5^2
But 3^3 + 4^3 is not 37, it's 91.
4^3 - 3^3 = 37, so the 3 is negative.
x = 4, y = -3
x + y = 1
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Or x = -3, y = 4
x + y = 1
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