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

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.