If 3 - 1 = 1 - 3 = 3, then the number 1 is called?

Additive inverse

Additive identify

Multiplication identity

None of these

The additive inverse of a number is what you add to a number to get zero.

In this context, 1 and -1 are additive inverses of each other, satisfying:

3 + (-1) = 2 and 1 - 3 = -2, showing the concept revolves around opposites in addition.