Find the center and radius of the circle x2+y2=49x^2 + y^2 = 49x2+y2=49.
Center: (0,0)(0,0)(0,0), Radius: 777
Center: (0,0)(0,0)(0,0), Radius: 494949
Center: (7,7)(7,7)(7,7), Radius: 777
Center: (7,0)(7,0)(7,0), Radius: 777