[tex]|a|= \left\{\begin{array}{ccc}a&for\ a\geq0\\-a&for\ a \ \textless \ 0\end{array}\right\\\\Examples:\\|2|=2\ because\ 2\geq0\\|0|=0\ because\ 0\geq0\\|-5|=-(-5)=5\ because\ -5 \ \textless \ 0\\|-100|=-100\ because\ -100 \ \textless \ 0[/tex]
|-3| + |3| = 3 + 3 = 6
