\(\Leftrightarrow4x^2-12x+9-8x^2+18=0\)
\(\Leftrightarrow-4x^2-12x+27=0\)
\(\Leftrightarrow4x^2-6x+18x-27=0\)
\(\Leftrightarrow2x\left(2x-3\right)+9\left(2x-3\right)=0\)
\(\Leftrightarrow\left(2x-3\right)\left(2x+9\right)=0\)
\(\left[{}\begin{matrix}3-2x=0\\2x+9=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=-\dfrac{9}{2}\end{matrix}\right.\)
Vậy ...