Question

Решите систему уравнений
{-x-y=3
{x^2+y^2=5

Answer 1

$left { {{-x-y=3} atop { x^{2} + y^{2}=5 }} right.$  ⇒ $left { {{x=-3-y} atop { (-3-y)^{2} + y^{2} =5 }} right.$ ⇒ $left { {{x=-3-y} atop {9+6y+2 y^{2}=5 }} right.$  ⇒$left { {{x=-3-y} atop { y^{2} +3y+2=0 }} right.$
D=9-8=1
y(1)=(-3+1)/2=-1
y(2)= -2
x(1)=-3-y(1)=-3+1=-2
x(2)=-3-y(2)=-3+2=-1
        ответ; (-2;-1), (-1;-2)