a /.
\(3x^2-8x-\left(6x-16\right)=0\)
\(\Leftrightarrow3x^2-8x-6x+16=0\)
\(\Leftrightarrow x\left(3x-8\right)-2\left(3x-8\right)=0\)
\(\Leftrightarrow\left(3x-8\right).\left(x-2\right)=0\).
\(\Rightarrow\left[{}\begin{matrix}3x-8=0\\x-2=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{8}{3}\\x=2\end{matrix}\right.\)
Vậy \(x=\dfrac{8}{3}\) hay \(x=2\)
b /.
\(2\left(3x-2\right)^2-9x^2+4=0\)
\(\Leftrightarrow2\left(9x^2-12x+4\right)-9x^2+4=0\)
\(\Leftrightarrow18x^2-24x+8-9x^2+4=0\)
\(\Leftrightarrow9x^2-24x+12=0\)
\(\Leftrightarrow9x^2-18x-6x+18=0\)
\(\Leftrightarrow9x\left(x-2\right)-6\left(x-2\right)=0\)
\(\Leftrightarrow\left(x-2\right)\left(9x-6\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x-2=0\\9x-6=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{2}{3}\end{matrix}\right.\)
Vậy \(x=2\) hay \(x=\dfrac{2}{3}\)
