\(\left|x-3\right|=\left|4-x\right|\)
\(\Leftrightarrow\left|x-3\right|=\left|-x+4\right|\)
\(\Leftrightarrow\left[{}\begin{matrix}x-3=-x+4\\x-3=-\left(-x+4\right)\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x+x=4+3\\x-3=x-4\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}2x=7\\x-x=-4+3\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{7}{2}\\x\in\varnothing\end{matrix}\right.\)
Vậy \(x=\dfrac{7}{2}\)