Giải thích các bước giải:
$\begin{array}{l} + Khi:x \ge 3\\ \Rightarrow \left\{ \begin{array}{l} \left| {2x - 6} \right| = 2x - 6\\ x + 3 = x + 3 \end{array} \right.\\ Pt:2x - 6 + x + 3 = 8\\ \Rightarrow 3x = 11\\ \Rightarrow x = \dfrac{{11}}{3}\left( {tm:x \ge 3} \right)\\ + Khi: - 3 \le x < 3 \Rightarrow \left\{ \begin{array}{l} \left| {2x - 6} \right| = 6 - 2x\\ \left| {x + 3} \right| = x + 3 \end{array} \right.\\ Pt:6 - 2x + x + 3 = 8\\ \Rightarrow - x = - 1\\ \Rightarrow x = 1\left( {tmdk} \right)\\ + Khi:x < - 3 \Rightarrow \left\{ \begin{array}{l} \left| {2x - 6} \right| = 6 - 2x\\ \left| {x + 3} \right| = - x - 3 \end{array} \right.\\ \Rightarrow 6 - 2x - x - 3 = 8\\ \Rightarrow 3x = - 5\\ \Rightarrow x = - \dfrac{5}{3}\left( {ktm} \right)\\ Vậy\,x = \dfrac{{11}}{3};x = 1 \end{array}$
