Решите уравнения( сложением и подстановкой)

1)[latex] left { {{ frac{x+y-xy}{xy(x+y)} = frac{1}{2} } atop {xy(x+y)=2}} ight. \ left { {{ x+y-xy = 1} atop {xy(x+y)=2}} ight.\ left { {{ (x-1)(1-y)=0 } atop {xy(x+y)=2}} ight.\[/latex]1) x = 1y(1+y)=2y² + y - 2 = 0D = 1 + 8 = 9y₁ = (-1-3)/2=-2y₂ = (-1+3)/2=1Ответ: (-2; 1); (1; -2); (1; 1)2)[latex] left { {{x(1+y)=3} atop {xy^2(1+y)=12}} ight. \ left { {{x(1+y)=3} atop {3y^2=12}} ight. \[/latex]y²= 4y₁ = -2y₂ = 2x₁(1-2)=3x₁ = -3x₂(1+2)=3x₂ = 1Ответ: (-3; -2); (1; 2)