`1) (x-2)(x-7)=0`

`<=>` \(\left[ \begin{array}{l}x-2=0\\x-7=0\end{array} \right.\) 

`<=>` \(\left[ \begin{array}{l}x=2\\x=7\end{array} \right.\) 

Vậy `x in {2;7}`

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

`<=>` \(\left[ \begin{array}{l}x-3=0\\x-5=0\end{array} \right.\) 

`<=>` \(\left[ \begin{array}{l}x=3\\x=5\end{array} \right.\) 

Vậy `x in {3;5}`

`3) 1007(3x-6)(x-9)=0`

`<=> (x-2)(x-9)=0`

`<=>` \(\left[ \begin{array}{l}x-2=0\\x-9=0\end{array} \right.\) 

`<=>` \(\left[ \begin{array}{l}x=2\\x=9\end{array} \right.\) 

Vậy `x in {2;9}`

`4) (2-x)(9x-72)=0`

`<=>` \(\left[ \begin{array}{l}2-x=0\\9x-72=0\end{array} \right.\) 

`<=>` \(\left[ \begin{array}{l}x=2\\x=8\end{array} \right.\) 

Vậy `x in {2;8}`

`5) (x-201)(x-202)=0`

`<=>` \(\left[ \begin{array}{l}x-201=0\\x-202=0\end{array} \right.\) 

`<=>` \(\left[ \begin{array}{l}x=201\\x=202\end{array} \right.\) 

Vậy `x in {201;202}`

`6) (14x-28)(3x-27)=0`

`<=> (x-2)(x-9)=0`

`<=>` \(\left[ \begin{array}{l}x-2=0\\x-9=0\end{array} \right.\)

`<=>` \(\left[ \begin{array}{l}x=2\\x=9\end{array}\right.\)  

Vậy `x in {2;9}`