a) Ta có: \(2n+1⋮6-n\)
\(\Rightarrow2n+1⋮-n+6\)
\(\Rightarrow2n-12+13⋮-n+6\)
\(\Rightarrow-2\left(-n+6\right)+13⋮-n+6\)
\(\Rightarrow13⋮-n+6\)
\(\Rightarrow6-n\in\left\{1;-1;13;-13\right\}\)
\(\Rightarrow n\in\left\{5;7;-7;19\right\}\)
Vậy \(n\in\left\{5;7;-7;19\right\}\)
b) \(\left|x-2017\right|-1=0\)
\(\Rightarrow\left|x-2017\right|=1\)
\(\Rightarrow\left[\begin{matrix}x-2017=1\\x-2017=-1\end{matrix}\right.\Rightarrow\left[\begin{matrix}x=2018\\x=2016\end{matrix}\right.\)
Vậy \(x\in\left\{2018;2016\right\}\)
A)Ta có:
(2n+1) chia hết cho 6-n
Suy ra:2(6-n)+13 chia hết cho 6-n
Suy ra:13 chia hết cho 6-n
Suy ra :n thuộc ước của 13
