问题
解答题
先化简，再求值．(
|
答案
∵x2+2x-4=0，
∴x（x+2）=4，
∵(
| 2 |
| x-2 |
| x-2 |
| x2-4x+4 |
| x2+2x |
| x-2 |
=(
| 2 |
| x-2 |
| x-2 |
| (x-2)2 |
| x-2 |
| x(x-2) |
=
| 2 |
| x(x+2) |
| 1 |
| x(x+2) |
| 1 |
| x(x+2) |
∴当x（x+2）=4时，原式=
| 1 |
| x(x+2) |
| 1 |
| 4 |
搜题请搜索小程序“爱下问搜题”
先化简，再求值．(
|
∵x2+2x-4=0，
∴x（x+2）=4，
∵(
| 2 |
| x-2 |
| x-2 |
| x2-4x+4 |
| x2+2x |
| x-2 |
=(
| 2 |
| x-2 |
| x-2 |
| (x-2)2 |
| x-2 |
| x(x-2) |
=
| 2 |
| x(x+2) |
| 1 |
| x(x+2) |
| 1 |
| x(x+2) |
∴当x（x+2）=4时，原式=
| 1 |
| x(x+2) |
| 1 |
| 4 |
