Question

What do you think would happen to the force if the distance is cut in half and each of the masses is also cut in half

Answer 1

The formula for the force of gravity has  ( M₁ · M₂ / D² )  in it.

After the changes, the new force will have  ( 0.5M₁ · 0.5M₂ / (0.5D)² ) .

We can separate the new numbers from the original force, like this:

                         ( 0.5M₁ · 0.5M₂ / (0.5D)² ) 

                     =  ( 0.5 · 0.5 / (0.5)² ) times ( M₁ · M₂ / D² )

The first factor boils down to ' 1 '.  So, those changes would
leave the strength of the force unchanged.

That's what I think.