两式相减(x+1)²-(x-2)²+(y+4)²-(y-2)²=25-10x²+2x+1-x²+4x-4+y²+8y+16-y²+4y-4=156x+12y+9=156x+12y=6x+2y=1x=1-2y代入①式(1-2y+1)²+(y+4)²=254y²-8y+4+y²+8y+16=255y²=5y=±1x=1-2=-1 或 x=1-(-1)x2=3所以 x=-1 y=1x=3 y=-1