`c)(x-2)/3+(2x^2-9x+10)/6=0`

`<=>(2(x-2))/6+(2x^2-9x+10)/6=9`

`<=>(2(x-2)+2x^2-9x+10)/6=0`

`<=>2(x-2)+2x^2-9x+10=0`

`<=>2x-4+2x^2-9x+10=0`

`<=>2x^2+(2x-9x)+(10-4)=0`

`<=>2x^2-7x+6=0`

`<=>2(x^2-7/2x+3)=0`

`<=>x^2-7/2x+3=0`

`<=>x^2-3/2x-2x+3=0`

`<=>(x-2)(x-3/2)=0`

`<=>`\(\left[ \begin{array}{l}x-2=0\\x-\dfrac{3}{2}=0\end{array} \right.\) 

`<=>`\(\left[ \begin{array}{l}x=2\\x=\dfrac{3}{2}\end{array} \right.\) 

Vậy `S={2;3/2}`