A)y=-2-x
-2-x-x2=-8
-2-x-x2+8=0
-x2-x+6=0
x2+x-6=0
D=1-4*(-6)=1+24=25=5²
x1=-1+5/2=2
x2=-1-5/2=-3
y1=-2-2=-4
y2=-2-(-3)=-2+3=1
b)y=5+2x
-6(5+2x)-x2=2
-30-12x-x2=2
-x2-12x-32=0
x2+12x+32=0
D=144-4*32=144-128=16=4²
x1=-12+4/2=-4
x2=-12-4/2=-8
y1=5+2*(-4)=5-8=-3
y2=5+2*(-8)=5-16=-11
c)y=-6+x
-4*(-6+x)-x2=3
24-4x-x2-3=0
-x2-4x+21=0
x2+4x-21=0
D=16-4*(-21)=16+84=100=10²
x1=-4+10/2=6/2=3
x2=-4-10/2=-14/2=-7
y1=-6+3=-3
y2=-6-7=-13