1) x²-y√xy=36
1a) x^(1/2)(x^(3/2) – y^(3/2)) = 36
2) y²-x√xy=72
2a) y^(1/2)(y^(3/2) – x^(3/2)) = 72
2a) -y^(3/2)(x^(3/2) – y^(3/2)) = 72
1a) x^(1/2)(x^(3/2) – y^(3/2)) = 36
2a) -y^(3/2)(x^(3/2) – y^(3/2)) = 72
1b) (x^(3/2) – y^(3/2)) = 36/x^(1/2)
2b) (x^(3/2) – y^(3/2)) = -72/y^(1/2)
Therefore 36/x^(1/2) = -72/y^(1/2) cross product gives
36y^(1/2) = -72x^(1/2)
y^(1/2) = -2(x^(1/2) square both sides
y = 4x