| 500 |
| a2−1 |
B玉米试验田面积是（a-1）2米2，单位面积产量是
| 500 |
| (a−1)2 |
∵a2-1-（a-1）2=2（a-1）
∵a-1＞0，∴0＜（a-1）2＜a2-1
∴
| 500 |
| a2−1 |
| 500 |
| (a−1)2 |
∴B玉米的单位面积产量高；
（2）
| 500 |
| (a−1)2 |
| 500 |
| a2−1 |
=
| 500 |
| (a−1)2 |
| a2−1 |
| 500 |
=
| (a+1)(a−1) |
| (a−1)2 |
=
| a+1 |
| a−1 |
∴高的单位面积产量是低的单位面积产量的
| a+1 |
| a−1 |
| 500 |
| a2−1 |
| 500 |
| (a−1)2 |
| 500 |
| a2−1 |
| 500 |
| (a−1)2 |
| 500 |
| (a−1)2 |
| 500 |
| a2−1 |
| 500 |
| (a−1)2 |
| a2−1 |
| 500 |
| (a+1)(a−1) |
| (a−1)2 |
| a+1 |
| a−1 |
| a+1 |
| a−1 |