| 2(a−b) |
| (a−b)2 |
| b |
| (a+b)(a−b) |
| a−b |
| 3b+2a |
=
| 2(a+b)(a−b)+b(a−b) |
| (a+b)(a−b)2 |
| a−b |
| 3b+2a |
=
| (a−b)(3b+2a) |
| (a+b)(a−b)2 |
| a−b |
| 3b+2a |
=
| 1 |
| a+b |
当a=5，b=2时，原式=
| 1 |
| 7 |
| 2a−2b |
| a2−2ab+b2 |
| b |
| a2−b2 |
| 3b+2a |
| a−b |
| 2(a−b) |
| (a−b)2 |
| b |
| (a+b)(a−b) |
| a−b |
| 3b+2a |
| 2(a+b)(a−b)+b(a−b) |
| (a+b)(a−b)2 |
| a−b |
| 3b+2a |
| (a−b)(3b+2a) |
| (a+b)(a−b)2 |
| a−b |
| 3b+2a |
| 1 |
| a+b |
| 1 |
| 7 |