Answer
The absolute value of number -13 is 13.
The opposite of number -13 is 13.
Work Step by Step
Since the absolute value of a number $A$ is that number's distance from 0 on the number line, if $A=-13$, then $|-13|=13$.
Since the opposite of a number $A$ is to put a negative sign in front of the number, if $A=-13, -A=-(-13)=13$.