| 1 |
| 9 |
| 3 |
| x9 |
| y-x |
| y9 |
| y-x |
| a9-1 |
| a9+9a+9 |
| a+1 |
| a+9 |
| x2-4 |
| xy+2y |
| x2-2x+1 |
| x2-1 |
| x-1 |
| x2+x |
| a |
| a2-2a |
| 1 |
| 3-a |
| 2-a |
| 9-a2 |
| 1 |
| 2 |
| 3 | 27 |
| 1 |
| 3 |
| 4xy |
| x+y |
| 4xy |
| x-y |
| 1 |
| 3 |
| 3 |
| 4 |
| x |
| x-y |
| 2y |
| x-y |
| xy |
| x-2y |
| 1 |
| x |
| 1 |
| y |
| a-b |
| a |
| 2ab-b2 |
| a |
| 1 |
| 2 |
| π |
| 15 |
| x-1 |
| x-4 |
| x-1 |
| 4 |
| 1 |
| 3 |
| 2a |
| a-1 |
| a |
| a-1 |
| 4 |
| a-1 |
| 8 |
| 3 |
| 3 |
| 8 |
| 8 |
| x+1 |
| x-1 |
| x+1 |
| a2 |
| a+b |
| b2 |
| a+b |
| 1 |
| 3 |
| x2+2x |
| x2+4x+4 |
| 1 |
| 3 |
| 2 |
| 9 |
| x2-2x |
| x2-4 |
| 2x |
| x+2 |