Ta có : \(\frac{x-3}{x-1}=\frac{x-1-2}{x-1}=1-\frac{2}{x-1}\)
Để \(\frac{x-3}{x-1}\) nguyên => \(\frac{2}{x-1}\) nguyên
=> 2 chia hết cho x - 1
=> x - 1 ∈ Ư(2)
=> x - 1 ∈ { ±1 ; ±2 }
- Nếu x - 1 = 1 => x = 2
- Nếu x - 1 = -1 => x = 0
- Nếu x - 1 = 2 => x = 3
- Nếu x - 1 = -2 => x = -1