x2+y2+10=0x^{2}+y^{2}+10=0x2+y2+10=0
(x−3)2+(y+2)2=−100(x-3)^{2}+(y+2)^{2}=-100(x−3)2+(y+2)2=−100
x2+y2+8x+6y+4=0x^{2}+y^{2}+8 x+6 y+4=0x2+y2+8x+6y+4=0
x2+y2+x+y+10=0x^{2}+y^{2}+x+y+10=0x2+y2+x+y+10=0