| 3 |
| x |
| 6 |
| x-1 |
| x+5 |
| x(x-1) |
| 3x-3+6x-x-5 |
| x(x-1) |
| 8(x-1) |
| x(x-1) |
| 8 |
| x |
（2）原式=
| x |
| (x-1)2 |
| x+1+x2-1 |
| (x+1)(x-1) |
| x |
| (x-1)2 |
| (x+1)(x-1) |
| x(x+1) |
| 1 |
| x-1 |
| 3 |
| x |
| 6 |
| 1-x |
| x+5 |
| x2-x |
| x |
| x2-2x+1 |
| x+1 |
| x2-1 |
| 3 |
| x |
| 6 |
| x-1 |
| x+5 |
| x(x-1) |
| 3x-3+6x-x-5 |
| x(x-1) |
| 8(x-1) |
| x(x-1) |
| 8 |
| x |
| x |
| (x-1)2 |
| x+1+x2-1 |
| (x+1)(x-1) |
| x |
| (x-1)2 |
| (x+1)(x-1) |
| x(x+1) |
| 1 |
| x-1 |