x2+y2+4x–6y+4=0x^2 + y^2 + 4x – 6y + 4 = 0x2+y2+4x–6y+4=0
x2+y2−4x+6y+4=0x^2 + y^2− 4x + 6y + 4 = 0x2+y2−4x+6y+4=0
x2+y2–4x+6y+9=0x^2 + y^2 – 4x + 6y + 9 = 0x2+y2–4x+6y+9=0
x2+y2+4x–6y+9=0x^2 + y^2 + 4x – 6y + 9 = 0x2+y2+4x–6y+9=0