For this exercise, you need to remember the definition of Absolute Value.
The Absolute Value of a number is defined as its distance from zero on the Number Line. By definition, a distance cannot be negative, therefore, the Absolute Value of a number is always a positive.
By definition, the set of Integers contains the positive numbers, the negative numbers are zero,
In this case, you have the following equation:

Notice that the Absolute Value of "n" (which is an Integer), is equal to 1.
Then, based on the definitions explained before, you know that:

Therefore, the answer is:
