Question

{x+y=-1, {x2+y2=1
решите?)

Answer 1

{x+y=-1 x=-1-y
{x2+y2=1
(-1-y)^2 +y^2-1=0
1+2y+y^2+y^2-1=0
2y(y+1)=0
2y=0 y+1=0
y=0 y=-1
x1=-1-0=-1
x2=-1-(-1)=-1+1=0
ж:(-1;0) (0;-1)

Answer 2

спасибо!)