## Functions Modeling Change: A Preparation for Calculus, 5th Edition

Let $f(x)=|x|$ and $g(x)=|-x|$. $|-x|$ can be rewritten as $|-x|=|x|$. So, $g(x)=|x|$. $f(x)=|x|$ also, so $f(x)=g(x)$, making the statement true.