| -x+y |
| -x-y |
| x-y |
| x+y |
| x-y |
| x+y |
| a |
| b |
| 3 |
| 2 |
| a+b |
| b |
| 1 |
| a |
| 1 |
| b |
| a+2ab+b |
| a-ab+b |
| 2x-3y+6z |
| 3x-2y+4z |
| 67 |
| 78 |
| 67 |
| 78 |
| 0.01-0.03x |
| 0.02 |
| x-3 |
| 2 |
| |x-2| |
| x-2 |
| |x-1| |
| 1-x |
| a2-3 |
| -2-a |
| a2-3 |
| a+2 |
| a2-3 |
| a+2 |
| x |
| 2 |
| y |
| 3 |
| z |
| 4 |
| 2x+y-z |
| 3x-2y+z |
| 3 |
| 4 |
| 3 |
| 4 |
| 它.人x-它.5y |
| x+人.5y |
| x-5y |
| 人它x+人5y |
| x-5y |
| 人它x+人5y |
| a |
| b |
| a个+b个 |
| ab |
| 19 |
| 3 |
| 19 |
| 3 |