2,a, \(12⋮2x+1\)
\(\Rightarrow2x+1\inƯ\left(12\right)=\left\{\pm1;\pm2;\pm3;\pm4;\pm6;\pm12\right\}\)
2x + 1 | 1 | -1 | 2 | -2 | 3 | -3 | 4 | -4 | 6 | -6 | 12 | -12 |
2x | 0 | -2 | 1 | -3 | 2 | -4 | 3 | -5 | 5 | -7 | 11 | -13 |
x | 0 | -1 | 1/2 | -3/2 | 1 | -2 | 3/2 | -5/2 | 5/2 | -7/2 | 11/2 | -13/2 |
Vì \(x\in N\)=> x = 0 ; 1
b, \(2x+6⋮2x-1\)
\(2x-1+7⋮2x-1\)
Vì \(2x-1⋮2x-1\)
\(7⋮2x-1\)=> \(2x-1\inƯ\left(7\right)=\left\{\pm1;\pm7\right\}\)
2x - 1 | 1 | -1 | 7 | -7 |
2x | 2 | 0 | 8 | -6 |
x | 1 | 0 | 4 | -3 |
Vì \(x\in N\)=> x = 1; 0 ; 4