Try the following ACT math practice question that tests your understanding of manipulating algebraic expressions with absolute value.

Given $m$ and $n$ are real numbers such that $m > n$, which of the following expressions equals $|n-m|$ ?

- $\quad n-m$
- $\quad m-n$
- $\quad -n-m$
- $\quad m+n$
- $\quad \sqrt{m^2-n^2}$

**Video Explanation**