\(\Rightarrow9n+1⋮n-2\)
\(\Rightarrow\left(9n-18\right)+19\)\(⋮n-2\)
\(\Rightarrow9\left(n-2\right)+19\)\(⋮n-2\)
Vì \(n-2\)\(⋮n-2\)
nên \(9\left(n-2\right)\)\(⋮n-2\)
\(\Rightarrow19\)\(⋮n-2\)
\(\Rightarrow n-2\in\left\{1;-1;19;-19\right\}\)
\(\Rightarrow n\in\left\{3;1;21;-17\right\}\)