What is the equation of the radical axis of the circles x2+y2+2x+1=0x^2 + y^2 + 2x + 1 = 0x2+y2+2x+1=0 and x2+y2+4y+2=0x^2 + y^2 + 4y + 2 = 0x2+y2+4y+2=0?
2x−4y−1=02x - 4y - 1 = 02x−4y−1=0
2x+4y+1=02x + 4y + 1 = 02x+4y+1=0
x−2y=0x - 2y = 0x−2y=0
x+2y+1=0x + 2y + 1 = 0x+2y+1=0