Ta có: (2x+5)(x-3)=(x-4)(3-x)
⇔(2x+5)(x-3)-(x-4)(3-x)=0
⇔(2x+5)(x-3)+(x-4)(x-3)=0
⇔(x-3)(2x+5+x-4)=0
⇔(x-3)(3x+1)=0
\(\Leftrightarrow\left[{}\begin{matrix}x-3=0\\3x+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\3x=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=\frac{-1}{3}\end{matrix}\right.\)
Vậy: \(x\in\left\{\frac{-1}{3};3\right\}\)