设该点坐标(x,y,0)√[(x-1)^2+(y+1)^2+5^2]=√[(x-3)^2+(y-4)^2+4^2]=√[(x-4)^2+(y-5)^2+1]=>x^2-2x+y^2+2y+27=x^2-6x+y^2-8y+41=x^2-8x+y^2-10y+42=>-2x+2y+27=-6x-8y+41=-8x-10y+42=>x=-1.5 y=2该点坐标(-1.5,2,0...