x2+y2+4x−6y+9=0x^{2}+y^{2}+4 x-6 y+9=0x2+y2+4x−6y+9=0
x2+y2−4x+6y+9=0x^{2}+y^{2}-4 x+6 y+9=0x2+y2−4x+6y+9=0
x2+y2+4x−6y+4=0x^{2}+y^{2}+4 x-6 y+4=0x2+y2+4x−6y+4=0
x2+y2−4x+6y+4=0x^{2}+y^{2}-4 x+6 y+4=0x2+y2−4x+6y+4=0