\(\left|x\right|< 6\Leftrightarrow\left|x\right|\in\left(1;2;3;4;5\right).\) 

\(\left|x\right|\notin\){ số tự nhiên âm }

\(\left|x\right|=1\Leftrightarrow\orbr{\begin{cases}x=1\\x=-1\end{cases}}\)vì \(\left|1\right|=1;\left|-1\right|=1\)

\(\left|x\right|=2\Leftrightarrow\orbr{\begin{cases}x=2\\x=-2\end{cases}}\)vì \(\left|2\right|=2;\left|-2\right|=2\)

\(\left|x\right|=3\Leftrightarrow\orbr{\begin{cases}x=3\\x=-3\end{cases}}\)vì \(\left|3\right|=3;\left|-3\right|=3\)

\(\left|x\right|=4\Leftrightarrow\orbr{\begin{cases}x=4\\x=-4\end{cases}}\)vì \(\left|4\right|=4;\left|-4\right|=4\)

\(\left|x\right|=5\Leftrightarrow\orbr{\begin{cases}x=5\\x=-5\end{cases}}\)vì \(\left|5\right|=5;\left|-5\right|=5\)