1) \(\left|x\right|-x=0\)
\(\Leftrightarrow\left|x\right|=x\)
\(\Leftrightarrow x\ge0\)
2) \(\left|x\right|+x=0\)
\(\Leftrightarrow\left|x\right|=-x\) hoặc \(\left|x\right|=x=0\)
\(\Leftrightarrow x\le0\). Vì n \(\in\) N nên n = 0
3) \(\left|x-2\right|