\(5x.\left(3x-2\right)=4-9x^2\)
\(\Rightarrow5x.\left(3x-2\right)-\left(4-9x^2\right)=0\)
\(\Rightarrow5x.\left(3x-2\right)+\left(9x^2-4\right)=0\)
\(\Rightarrow5x.\left(3x-2\right)+\left(3x-2\right).\left(3x+2\right)=0\)
\(\Rightarrow\left(3x-2\right).\left(5x+3x+2\right)=0\)
\(\Rightarrow\left(3x-2\right).\left(8x+2\right)=0\)
\(\Rightarrow\orbr{\begin{cases}3x-2=0\\8x+2=0\end{cases}}\Rightarrow\orbr{\begin{cases}3x=2\\8x=-2\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{2}{3}\\x=\frac{-1}{4}\end{cases}}\)