问题
解答题
先化简，再求值：
|
答案
| x2-4 |
| x2-4x+4 |
| x2-x |
| x-1 |
=
| (x-2)(x+2) |
| (x-2) 2 |
| x(x-1) |
| x-1 |
| 1 |
| x |
=
| x+2 |
| x-2 |
=
| 2x |
| x-2 |
当x=
| 3 |
| 2 |
| 2x |
| x-2 |
2×
| ||
|
搜题请搜索小程序“爱下问搜题”
先化简，再求值：
|
| x2-4 |
| x2-4x+4 |
| x2-x |
| x-1 |
=
| (x-2)(x+2) |
| (x-2) 2 |
| x(x-1) |
| x-1 |
| 1 |
| x |
=
| x+2 |
| x-2 |
=
| 2x |
| x-2 |
当x=
| 3 |
| 2 |
| 2x |
| x-2 |
2×
| ||
|