( 2x + 5 )(x - 4) = (x - 5)( 4 - x )
<=> 2x2 - 8x + 5x - 20 = 4x - x2 - 20 + 5x
<=> 3x2 - 12x = 0
<=> 3x( x - 4 ) = 0
<=> \(\left[{}\begin{matrix}3x=0\\x-4=0\end{matrix}\right.< =>\left[{}\begin{matrix}x=0\\x=4\end{matrix}\right.\)
Vậy phương trình có nghiệm \(\left[{}\begin{matrix}x=0\\x=4\end{matrix}\right.\)