题目：
（2013·丹阳市二模）（1）计算：| 9 |
| 1 |
| 3 |
（2）化简：
| a2-1 |
| 3a |
| 2a-1 |
| a |
答案
解：（1）| 9 |
| 1 |
| 3 |
=3+2×
| 1 |
| 2 |
=0；
（2）
| a2-1 |
| 3a |
| 2a-1 |
| a |
=
| (a+1)(a-1) |
| 3a |
| a |
| (a-1)2 |
=
| a+1 |
| 3(a-1) |
解：（1）
| 9 |
| 1 |
| 3 |
=3+2×
| 1 |
| 2 |
=0；
（2）
| a2-1 |
| 3a |
| 2a-1 |
| a |
=
| (a+1)(a-1) |
| 3a |
| a |
| (a-1)2 |
=
| a+1 |
| 3(a-1) |
| 9 |
| 1 |
| 3 |
| a2-1 |
| 3a |
| 2a-1 |
| a |
| 9 |
| 1 |
| 3 |
| 1 |
| 2 |
| a2-1 |
| 3a |
| 2a-1 |
| a |
| (a+1)(a-1) |
| 3a |
| a |
| (a-1)2 |
| a+1 |
| 3(a-1) |
| 9 |
| 1 |
| 3 |
| 1 |
| 2 |
| a2-1 |
| 3a |
| 2a-1 |
| a |
| (a+1)(a-1) |
| 3a |
| a |
| (a-1)2 |
| a+1 |
| 3(a-1) |
（2009·三明）如图，△ABC是边长为2的等边三角形，将△ABC沿射线BC向右平移得到△DCE，连接AD、BD，下列结论错误的是（ ）