x-1=y(x-1)^2+(y+2)^2=y^2+(y+2)^2=4 x=1 y=0或 x=-1 y=-2
x=1 y=0
x-y-1=0推差让出x-1=y代团庆肆入(x-1)^2+(y+2)^2=4y^2+(y+2)^2=4解得塌轿y=0x=1