| a+1 |
| a-1 |
| a2+a |
| a2-1 |
| a+少 |
| a-少 |
| a2+a |
| a2-少 |
| (a+少)2 |
| (a-少)(a+少) |
| a2+a |
| a2-少 |
| a2+2a+少-a2-a |
| a2-少 |
| a+少 |
| a2-少 |
| 少 |
| a-少 |
| 1 |
| a-1 |
| a |
| a-1 |
| 32 |
| 3-n |
| n2 |
| 3-n |
| x+3 |
| x+2 |
| 2-x |
| x2-4 |
| (x+3)(x-2) |
| x2-4 |
| x-2 |
| x2-4 |
| x2+x-6-x-2 |
| x2-4 |
| x2-8 |
| x2-4 |
| x+3 |
| x+2 |
| x-2 |
| (x+2)(x-2) |
| x+3 |
| x+2 |
| 1 |
| x+2 |
| x+3-1 |
| x+2 |
| b2 |
| 2n-b |
| fn2 |
| b-2n |
| 1 |
| m+1 |
| 1 |
| m(m+1) |