x2+y2+6x-10y+34=0x2+6x+9+y2-10y+25=0（x+3）*2+（y-5）*2=0 x=-3、y=5 xy=-15
x^2+6x+9+y^2-10y+25=0 (x+3)^2+(y-5)^2=0 x=-3 y=5 xy=-15
