M1 is a spherical mass (43.0 kg) at the origin. M2 is also a spherical mass

M1 is a spherical mass (43.0 kg) at the origin. M2 is also a spherical mass (17.2 kg) and is located on the x-axis at x = 99.0 m. At what value of x would a 16.5-kg mass experience no net gravitational force due to M1 and M2?