x^2 + y^2 - 2xy = 36
x + y = -4
(x-y)^2=36
x+y=-4
1)x-y=6
x=6+y
6+y+y=-4
6+2y=-4
2y=-10
y=-5
x=6+(-5)=6-5
x=1
2) x-y=-6
x=y-6
y-6+y=-4
2y-6=-4
2y=-4+6
2y=2
y=1
x=1-6
x=-5
x1=1 y1=-5
x2=-5 y2=1
x^2 + y^2 - 2xy = 36
x + y = -4
(x-y)^2=36
x+y=-4
1)x-y=6
x+y=-4
x=6+y
6+y+y=-4
6+2y=-4
2y=-10
y=-5
x=6+y
x=6+(-5)=6-5
x=1
2) x-y=-6
x+y=-4
x=y-6
y-6+y=-4
2y-6=-4
2y=-4+6
2y=2
y=1
x=y-6
x=1-6
x=-5
x1=1 y1=-5
x2=-5 y2=1