Question

Решите систему
x+y=3
y↑2-xy=-1

Answer 1

$left { {{x+y=3} atop { y^{2}-xy =-1}} right. x=3-y y^{2} -y(3-y)=-1 y^{2} -3y+ y^{2} =-1 2 y^{2} -3y +1=0 D= sqrt{9-8} = sqrt{1} =1 y_{1}= frac{3+1}{4} =1 y_{2} = frac{3-1}{4} = frac{1}{2} x_{1} =3-1=2 x_{2} = 3- frac{1}{2} =2.5$