a) |x|-9 = -2+17
⇔ |x|-9 = 15
⇔ |x| = 15+9
⇔ |x| = 24
⇒ \(\left[ \begin{array}{l}x=24\\x=-24\end{array} \right.\)
Vậy \(\left[ \begin{array}{l}x=24\\x=-24\end{array} \right.\)
b) |x-9| = -2+17
⇔ |x-9| = 15
⇒ \(\left[ \begin{array}{l}x-9=15\\x-9=-15\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=15+9\\x=-15+9\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=24\\x=6\end{array} \right.\)
Vậy \(\left[ \begin{array}{l}x=24\\x=6\end{array} \right.\)
