A) y=2x-2 2x^2-2x^2-2x=6 2x=-6 x=-3 y=-8
б) x=6-2y (8-2y)(y+1)=12 6y-2y^2+8=0
y^2-3y-4=0 D=9+16=25 y1=4 y2=-1
x1=-2 x2=8
в) x^2+y^2=(x+y)^2-2xy
x^2+y^2=(x+y)^2+6=10
( x+y)^2=4
x+y=2 x=2-y=-3/y y^2-2y-3=0 D=4+12=16 y1=3 y2=-1 x1=-1 x2=3
x+y=-2 x=-2-y=-3/y y^2+2y-3=0 D=4+12=16 y1=1 y2=-3 x1=-3 x2=1