\(\left(3x-2\right)\left(2x+1\right)-\left(2x+1\right)^2=0\)
\(\Leftrightarrow\left(2x+1\right)\left(3x-2-2x-1\right)=0\Leftrightarrow\left(2x+1\right)\left(x-3\right)=0\Leftrightarrow x=-\dfrac{1}{2};x=3\)
\(\left(3x-2\right)\left(2x+1\right)=\left(2x+1\right)^2\\ \Leftrightarrow\left(3x-2\right)\left(2x+1\right)-\left(2x+1\right)^2=0\\ \Leftrightarrow\left(2x+1\right)\left(3x-2-2x-1\right)=0\\ \Leftrightarrow\left(2x+1\right)\left(x-3\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}2x+1=0\\x-3=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=3\end{matrix}\right.\)
