`x(2x-7) + 14 =4x`
$⇔x\left(2x-7\right)-4x+14=0$
$⇔x\left(2x-7\right)-2\left(2x-7\right)=0$
$⇔\left(x-2\right)\left(2x-7\right)=0$
$⇔ \left[{}\begin{matrix}x-2=0\\2x-7=0\end{matrix}\right.$
$⇔\left[{}\begin{matrix}x=2\\2x=7\end{matrix}\right.$
$⇔\left[{}\begin{matrix}x=2\\x=\dfrac{7}{2}\end{matrix}\right.$
Vậy `x=2;x=7/2`
Xin hay nhất !