"Each piece contains the same number of atoms" is the one statement among the following choices given in the question that correctly describes these broken pieces of the sample. The correct option among all the options that are given in the question is the penultimate option or the third option. I hope it helps you.
The solutions of given equation are -3, -1 and 3.
[-2] - [4-15]
= [-2] - [-11]
= -2 + 11 = 9