\(c,10⋮2x+1\)
\(\Rightarrow2x+1\inƯ\left(10\right)=\left\{\pm1;\pm2;\pm5;\pm10\right\}\)
Ta có bảng
| 2x+1 | 1 | -1 | 2 | -2 | 5 | -5 | -10 | 10 |
| 2x | 0 | -2 | 1 | -3 | 4 | -6 | -11 | 9 |
| x | 0 | -1 | 1/2 | -3/2 | 2 | -3 | -11/2 | 9/2 |
\(d,x+13⋮x+1\)
\(x+1+12⋮x+1\)
\(\Rightarrow x+1⋮x+1\)
\(\Rightarrow12⋮x+1\)
\(\Rightarrow x+1\inƯ\left(12\right)=\left\{\pm1;\pm2;\pm3;\pm4;\pm6;\pm12\right\}\)
Ta có bảng
| x+1 | 1 | -1 | 2 | -2 | 3 | -3 | 4 | -4 | 6 | -6 | 12 | -12 |
| x | 0 | -2 | 1 | -3 | 2 | -4 | 3 | -5 | 5 | -7 | 11 | -13 |
Bn tự KL cả 2 phần ...
\(f,2x+108⋮2x+3\)
\(\Rightarrow\left(2x+3\right)+105⋮2x+3\)
\(\Rightarrow2x+3⋮2x+3\)
\(\Rightarrow105⋮2x+3\)
\(\Rightarrow2x+3\inƯ\left(105\right)=\left\{\pm1;\pm3;\pm7;\pm15;\pm21;\pm35;\pm105\right\}\)
Ta lập bảng xét
| 2x+3 | 1 | -1 | 3 | -3 | 7 | -7 | 15 | -15 | 21 | -21 | 35 | -35 | 105 | -105 |
| 2x | -2 | -4 | 0 | -6 | 4 | -10 | 12 | -18 | 18 | -24 | 32 | -38 | 102 | -108 |
| x | -1 | -2 | 0 | -3 | 2 | -5 | 6 | -9 | 9 | -12 | 16 | -19 | 51 | -54 |
Tự KL ....
\(m,3x+4⋮x+1\)
\(3.\left(x+1\right)+3⋮x+1\)
\(\Rightarrow3.\left(x+1\right)⋮x+1\)
\(\Rightarrow3⋮x+1\)
\(\Rightarrow x+1\inƯ\left(3\right)=\left\{\pm1;\pm3\right\}\)
Ta lập bảng
| x+1 | 1 | -1 | 3 | -3 |
| x | 0 | -2 | 2 | -4 |
( hăm chắc )
Tự KL ........
