| 1 |
| a+1 |
| a+2 |
| a2−1 |
| (a+1)(a+2) |
| a2−2a+1 |
| 1 |
| a+1 |
| a+2 |
| (a+1)(a−1) |
| (a−1)2 |
| (a+1)(a+2) |
| 1 |
| a+1 |
| a−1 |
| (a+1)2 |
| 2 |
| (a+1)2 |
∵a2+2a-15=0，
∴（a+1）2=16，
∴原式=
| 2 |
| 16 |
| 1 |
| 8 |
| 1 |
| a+1 |
| a+2 |
| a2−1 |
| (a+1)(a+2) |
| a2−2a+1 |
| 1 |
| a+1 |
| a+2 |
| a2−1 |
| (a+1)(a+2) |
| a2−2a+1 |
| 1 |
| a+1 |
| a+2 |
| (a+1)(a−1) |
| (a−1)2 |
| (a+1)(a+2) |
| 1 |
| a+1 |
| a−1 |
| (a+1)2 |
| 2 |
| (a+1)2 |
| 2 |
| 16 |
| 1 |
| 8 |