\(2n-1⋮9-n\)
\(\Rightarrow9\left(2n-1\right)⋮9-n\)
\(\Rightarrow18n-9⋮9-n\)
\(\Rightarrow\left(18n+9\right)-9⋮9-n\)
\(\Rightarrow2\left(9-n\right)-9⋮9-n\)
\(\Rightarrow-9⋮9-n\)
\(9-n\inƯ\left(-9\right)=\left\{-9;-1;1;9\right\}\)
\(9-n\) | \(-9\) | \(-1\) | \(+1\) | \(+9\) |
\(n\) | \(0\) | \(8\) | \(10\) | \(18\) |