| 2 |
| a+1 |
| a-2 |
| a2-1 |
| a2-2a |
| a2-2a+1 |
| 2 |
| a+1 |
| a-2 |
| (a+1)(a-1) |
| (a-1)2 |
| a(a-2) |
| 2 |
| a+1 |
| a-1 |
| a(a+1) |
| 2a-a+1 |
| a(a+1) |
| 1 |
| a |
| 1 |
| 2012 |
| 2 |
| a+1 |
| a-2 |
| (a+1)(a-1) |
| (a-1)2 |
| a(a-2) |
| 2 |
| a+1 |
| a-1 |
| a(a+1) |
| 2a-a+1 |
| a(a+1) |
| 1 |
| a |
| 1 |
| 2012 |
| m2-n2 |
| mn |
| 1 |
| m+n |
| 1 |
| m-n |
| n |
| m2-n2 |
| 2mn+n2 |
| m2 |
| 1 |
| a2 |
| 1 |
| a |
| 1 |
| a |
| 1 |
| a2 |
| 1 |
| a |
| y4 |
| y8-3y4+1 |
| x2+4x+4 |
| x+2 |
| 2 |
| a |
| a2-3a |
| 2a |
| a2-9 |
| a-2 |
| a2+6a+9 |
|