Giải phương trình |7x-4|=|3x-4|

* Hướng dẫn giải

$\begin{array}{l}\left|7x-4\right|=\left|3x-4\right|\\ \Rightarrow \left[\begin{array}{l}7x-4=3x-4\\ 7x-4=4-3x\end{array}\right.\iff \left[\begin{array}{l}4x=0\\ 10x=8\end{array}\right.\iff \left[\begin{array}{l}x=0\\ x=\frac{4}{5}\end{array}\right.S=\left\{0;\frac{4}{5}\right\}\end{array}$