Answer:
F/9
Step-by-step explanation:
F = GmM/ d² where F is the force due to gravity, F₂ = is the force due to gravity when d in meters, the distance from the center of the earth is 3d and G is gravitional constant in Nm²/kg²
F₂ = GmM / (3d)² = GmM/ 9d²
make d² subject of the formula in the first formula
d² = GmM/ F
substitute this into the second formula
F₂ = GmM / 9( GmM / F) = GmM × (F /9GmM)
cancel GmM
F₂ = F/9