Question

True or False? When n is a negative integer, n - n = 0. Justify your response.

Answer 1

Regardless if n is positive or negative, when you subtract a number from itself the result will always be zero.

Answer 2

True.
For example let's say n is -1
-1 - - 1 =0
-1+ 1 = 0
This is true as -1 + 1 = 0