`9x^2 . ( 2x - 3 ) = 0`

`<=> [(9x^2 =0),(2x-3=0):}`

`<=> [(x^2 =0),(2x=3):}`

`<=>` $\left[\begin{matrix} x=0\\ x=\dfrac{3}{2}\end{matrix}\right.$

Vậy `S = { 0 ;3/2 }`