|-x|=5
⇔|x|=5
⇔\(\left[ \begin{array}{l}-x=5\\x=5\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=-5\\x=5\end{array} \right.\)
|x|=$\frac{2}{3}$
⇔\(\left[ \begin{array}{l}-x=$\frac{2}{3}$ \\x=$\frac{2}{3}$ \end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=-$\frac{2}{3}$ \\x=$\frac{2}{3}$ \end{array} \right.\)
|-x|=|-3|
⇔|x|=|3|
⇔\(\left[ \begin{array}{l}-x=3\\x=3\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=-3\\x=3\end{array} \right.\)
|2x|=|$\frac{-9}{7}$ |
⇔|2x|=|$\frac{9}{7}$ |
⇔\(\left[ \begin{array}{l}-(2x)=\frac{9}{7}\\2x=\frac{9}{7}\end{array}\right.\)
⇔\(\left[ \begin{array}{l}x=-\frac{9}{14} \\x= \frac{9}{14} \end{array} \right.\)
