| ab |
| a-b |
| a2 |
| a-b |
| 1 |
| x+1 |
| 1 |
| x-1 |
| 2 |
| x2-1 |
| 3 |
| 3 |
| 3 | -x |
| (-2)2 |
| x |
| x-y |
| y2 |
| x+y |
| x大y |
| x大-y大 |
| x2 |
| x2+y2 |
| x+n |
| xe-x |
| x |
| xe-ex+n |
| n |
| x |
| 4 |
| x2-4 |
| 2 |
| x+2 |
| 1 |
| 2-x |
| 1 |
| 2m |
| 1 |
| m+n |
| m+n |
| 2m |
| x2+xy |
| xy |
| x-y |
| y |
| x |
| x-2 |
| x |
| x+2 |
| 4x |
| x+2-x2 |
| 2x |
| x-3 |
| x |
| x+3 |
| x |
| x2-9 |
| 3 |
| 2 |
| 0 |
| 2 |
| 3 |
| 2 |
| 0 |
| 2 |
| 9 |
| 3 |
| 0 |
| 3 |
| 9 |
| 3 |
| 0 |
| 3 |
| 9 |
| 9 |
| 0 |
| 9 |
| 9 |
| 9 |
| 0 |
| 9 |
| m-3 |
| 3m-6m |
| 5 |
| m-2 |