| x(x+9) |
| x(x+3) |
| (x+3)(x−3) |
| (x+3)2 |
| x+9 |
| x+3 |
| x−3 |
| x+3 |
| 2(x+3) |
| x+3 |
（2）原式=-
| x−2 |
| x−1 |
| x2−4 |
| x−1 |
| x−2 |
| x−1 |
| x−1 |
| (x+2)(x−2) |
| 1 |
| x+2 |
| x2+9x |
| x2+3x |
| x2−9 |
| x2+6x+9 |
| 2−x |
| x−1 |
| 3 |
| x−1 |
| x(x+9) |
| x(x+3) |
| (x+3)(x−3) |
| (x+3)2 |
| x+9 |
| x+3 |
| x−3 |
| x+3 |
| 2(x+3) |
| x+3 |
| x−2 |
| x−1 |
| x2−4 |
| x−1 |
| x−2 |
| x−1 |
| x−1 |
| (x+2)(x−2) |
| 1 |
| x+2 |