Three point particles, with masses 5.00 kg, 4.00 kg and 7.00 kg are located on the x-y plane at coordinates ( 5.00 m, 6.00 m), ( 7.00 m, 8.00 m) and (x, y) m, respectively, in a uniform gravitational eld such that the center of gravity is located at the origin. The value of the y-coordinate is n m