Work Step by Step
The additive inverse of a number $a$ is $-a$. Therefore, the additive inverse of -12 is $-(-12)=12$. The absolute value of a number $a$ is equal to $a$ if $a\geq0$ and is equal to $-a$ if $a\lt0$. Therefore, $|-12|=-(-12)=12$. Recall that $-(-a)=a$.