Đáp án`+`Giải thích các bước giải:

 `9, 6(x - 2)(x - 4)(1 - 7x) = 0`

`<=> (x - 2)(x - 4)(1 - 7x) = 0`

`<=>` $\left[\begin{matrix} x-2= 0\\ x-4=0\\1 - 7x = 0\end{matrix}\right.$

`<=>` $\left[\begin{matrix} x=2\\ x=4\\x = \dfrac{1}{7}\end{matrix}\right.$

Vậy `S= {2;4;1/7}`

`10, (14 - 2x)^2 (3 -x)(2x - 4) = 0`

`<=>` $\left[\begin{matrix} (14 - 2x)^2 = 0\\ 3 -x= 0\\2x - 4= 0\end{matrix}\right.$

`<=>` $\left[\begin{matrix} 14 - 2x= 0\\ x=3\\2x= 4\end{matrix}\right.$

`<=>` $\left[\begin{matrix} x=7\\ x=3\\x= 2\end{matrix}\right.$

Vậy `S= {7;2;3}`

`11, (3x - 2)^2 (x +1)(x - 2) = 0`

`<=>` $\left[\begin{matrix} (3x- 2)^2 = 0\\ x+1= 0\\x - 2=0\end{matrix}\right.$

`<=>` $\left[\begin{matrix} 3x - 2= 0\\ x=-1\\x = 2\end{matrix}\right.$

`<=>` $\left[\begin{matrix} x=\dfrac{2}{3}\\ x =-1\\x = 2\end{matrix}\right.$

Vậy `S= {2/3;-1;2}`

`12, (3x - 3)^3 (x + 4) = 0`

`<=>` $\left[\begin{matrix} (3x - 3)^3 = 0\\ x+4 = 0\end{matrix}\right.$

`<=>` $\left[\begin{matrix} 3x -3 =0\\ x=-4\end{matrix}\right.$

`<=>` $\left[\begin{matrix} x=1\\ x=-4\end{matrix}\right.$

Vậy `S = {1;-4}`

`13, (4x- 8)^2 ( 2x +6)^3= 0`

`<=>` $\left[\begin{matrix} (4x- 8)^2 = 0\\ (2x + 6)^3 = 0\end{matrix}\right.$

`<=>` $\left[\begin{matrix} 4x- 8 =0\\ 2x +6= 0\end{matrix}\right.$

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

Vậy `S= {2;-3}`

`14, (1/2x + 1)^3 (3x - 2)^2 =0`

`<=>` $\left[\begin{matrix} (\dfrac{1}{2}x + 1)^3 = 0\\ (3x - 2)^2= 0\end{matrix}\right.$

`<=> `$\left[\begin{matrix} \dfrac{1}{2}x + 1= 0\\ 3x- 2= 0\end{matrix}\right.$

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

Vậy `S= {-2;2/3}`

`***`sharksosad