∴
| 1 |
| 3xy3 |
| 6x2 |
| 3xy3•6x2 |
| 6x2 |
| 18x3y3 |
| 1 |
| 2x2y |
| 9xy2 |
| 2x2y•9xy2 |
| 9xy2 |
| 18x3y3 |
| 1 |
| 9x3y |
| 2y2 |
| 9x3y•2y2 |
| 2y2 |
| 18x3y3 |
（2）∵最简公分母是（a-b）（a+b）2，
∴
| 1 |
| (a+b)2 |
| a−b |
| (a+b)2(a−b) |
| 2 |
| −a+b |
| 2 |
| a−b |
| 2(a+b)2 |
| (a+b)2(a−b) |
| 3 |
| a2−b2 |
| 3 |
| (a+b)(a−b) |
| 3(a+b) |
| (a+b)2(a−b) |
| 1 |
| 3xy3 |
| 1 |
| 2x2y |
| 1 |
| 9x3y |
| 1 |
| (a+b)2 |
| 2 |
| −a+b |
| 3 |
| a2−b2 |
| 1 |
| 3xy3 |
| 6x2 |
| 3xy3•6x2 |
| 6x2 |
| 18x3y3 |
| 1 |
| 2x2y |
| 9xy2 |
| 2x2y•9xy2 |
| 9xy2 |
| 18x3y3 |
| 1 |
| 9x3y |
| 2y2 |
| 9x3y•2y2 |
| 2y2 |
| 18x3y3 |
| 1 |
| (a+b)2 |
| a−b |
| (a+b)2(a−b) |
| 2 |
| −a+b |
| 2 |
| a−b |
| 2(a+b)2 |
| (a+b)2(a−b) |
| 3 |
| a2−b2 |
| 3 |
| (a+b)(a−b) |
| 3(a+b) |
| (a+b)2(a−b) |