Ta có:
\(2n^2+5n-1⋮2n-1\)
\(\Rightarrow n\left(2n-1\right)+3\left(2n-1\right)+2⋮2n-1\)
\(\Rightarrow2⋮2n-1\)
Do \(n\in Z\Rightarrow2n-1\inƯ\left(2\right)=\left\{\pm1;\pm2\right\}\Rightarrow2n\in\left\{0;2;-1;3\right\}\)
Mà \(n\in Z\Rightarrow n\in\left\{0;1\right\}\)