Simplify $B=\sqrt{x^2} - x$

Question

I have to simplify the following expression:

$B=\sqrt{x^2} - x$

The only thing that I can do is:

$\sqrt{a^2}=|a|$, thus $B=|x|-x$. Is that enough?

Answer 1

$B=0$ if $x\geq0$ and $B=-2x$ if $x\leq 0$