\(\Leftrightarrow\)2(9x2+6x+1)=(3x+1)(x-2)
\(\Leftrightarrow\)2(3x+1)2-(3x+1)(x-2)=0
\(\Leftrightarrow\)(3x+1)[2(3x+1)-(x-2)]=0
\(\Leftrightarrow\)(3x+1)(6x+2-x+2)=0
\(\Leftrightarrow\)(3x+1)(5x+4)=0
\(\Leftrightarrow\)\(\orbr{\begin{cases}3x+1=0\Leftrightarrow3x=-1\Leftrightarrow x=\frac{-1}{3}\\5x+4=0\Leftrightarrow5x=-4\Leftrightarrow x=\frac{-4}{5}\end{cases}}\)