M8A5: b.Solve systems of equations algebraically and graphically

X2 + Y2 =100
(y+2)2 +Y2 =100
Y2+4Y+4+Y2=100
2Y2+4Y+4=100
2Y2+4Y-96=0
2(Y2+2Y-48)=0
2(y-6)(y+8)=0

y-6=0                    y+8=0
                or
y=6                        y=-8