$-15 - |3 - x| = -19 $
⇒ $|3 - x| =-15-(-19)$
⇒ $|3 - x| =-15+19$
⇒ $|3 - x| =4$
⇒ \(\left[ \begin{array}{l}3-x=4\\3-x=-4\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=3-4\\x=3-(-4)\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=-1\\x=7\end{array} \right.\)
Vậy $x=-1$ hoặc $x=7$