`x(3x + 5) - 6x - 10 = 0`

`=> x(3x + 5) - (6x + 10) = 0`

`=> x(3x + 5) - 2(3x + 5) = 0`

`=> (3x + 5)(x - 2) = 0`

`=>` $\left[\begin{matrix} 3x + 5 = 0\\ x-2=0\end{matrix}\right.$

`=>` $\left[\begin{matrix} 3x=-5\\ x=2\end{matrix}\right.$

`=>` $\left[\begin{matrix} x=-5/3\\ x=2\end{matrix}\right.$

Vậy $\left[\begin{matrix} x=-5/3\\ x=2\end{matrix}\right.$