| a |
| a+2 |
| 2 |
| a-2 |
| a2+2a |
| a2+4 |
| 1 |
| a |
| 1 |
| a |
| a+1 |
| a-1 |
| 1 |
| a2-2a+1 |
| a |
| a-1 |
| 1 |
| 2x-1 |
| x |
| 1-2x |
| 1-2x+x2 |
| 1-2x |
| x-2 |
| x-1 |
| x-2 |
| x |
| x-3 |
| 2x-4 |
| 5 |
| x-2 |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| n |
| 1 |
| n |
| 1 |
| 1×2 |
| 1 |
| 2×3 |
| 1 |
| 3×手 |
| 1 |
| n(n+1) |
| 7 |
| 12 |
| m2+n2 |
| m2-2mn+n2 |
| 2 |
| mn |
| 如 |
| m |
| 如 |
| n |
| 8 |
| 3 |
| 手+2 |
| 3 |
| 2 |
| 3 |
| 2 |
| 3 |
| x-1 |
| x+1 |
| x2 |
| x-1 |
| 3 |
| x+1 |
| 2x |
| x2+1 |
| x-1 |
| x+1 |
| (x+1)-2 |
| x+1 |
| 2 |
| x+1 |
| x2 |
| x-1 |
| x2-1+1 |
| x-1 |
| (x+1)(x-1)+1 |
| x-1 |
| 1 |
| x-1 |
| 2 |
| x |
| x-1 |
| x+2 |
| 3 |
| x+2 |
| 3 |
| x+2 |
| 2x-1 |
| x+1 |
| 1 |
| a |
| a-1 |
| a |
| x2-4 |
| x2-4x+4 |
| x-2 |
| x2+4x+4 |