|x-7|=2x+3

* Hướng dẫn giải

$\begin{array}{l}\left|x-7\right|=2x+3\left(3\right)\\ -)x\ge 7\Rightarrow \left(3\right)\iff x-7=2x+3\iff x=-10(ktm)\\ -)x<7\Rightarrow \left(3\right)\iff 7-x=2x+3\iff x=\frac{4}{3}(tm)\end{array}$