Theo đề ra ta có :
\(12⋮\left(n-1\right)\)
\(\Rightarrow\left(x-1\right)\inƯC\left(12\right)\)
\(ƯC\left(12\right)=\left\{-1;-2;-3;-4;-6;-12;1;2;3;4;6;12\right\}\)
vì \(x\in N\Rightarrow\left(x-1\right)=1;2;3;4;6;12\)
| x-1 | x |
| 1 | 2 |
| 2 | 3 |
| 3 | 4 |
| 4 | 5 |
| 6 | 7 |
| 12 | 13 |
Vậy x = 2;3;4;5;7;13