题目内容
（1）化简：
-
（2）先化简：
+
÷x，再在x=0，1，2，3中取一个你喜欢的x值代入求值．
| 1 |
| x+1 |
| 2x+1 |
| 1-x2 |
（2）先化简：
| x2-1 |
| x2-2x+1 |
| x2-2x |
| x-2 |
（1）原式=
+
=
+
=
=
；
（2）原式=
+
•
=
+1
=
，
当x=2时，原式=
=4．
| 1 |
| x+1 |
| 2x+1 |
| (x+1)(x-1) |
=
| x-1 |
| (x+1)(x-1) |
| 2x+1 |
| (x+1)(x-1) |
=
| x-1+2x+1 |
| (x+1)(x-1) |
=
| 3x |
| x2-1 |
（2）原式=
| (x+1)(x-1) |
| (x-1)2 |
| x(x-2) |
| x-2 |
| 1 |
| x |
=
| x+1 |
| x-1 |
=
| 2x |
| x-1 |
当x=2时，原式=
| 2x |
| x-1 |
练习册系列答案
相关题目