题目内容
化简
-
的结果是( )
| x |
| x-1 |
| 1 |
| x+1 |
| A.1 | B.x2+1 | C.x2-1 | D.
|
原式=
-
=
=
.
故选:D.
| x(x+1) |
| (x-1)(x+1) |
| x-1 |
| (x+1)(x-1) |
=
| x2+x-x+1 |
| x2-1 |
=
| x2+1 |
| x2-1 |
故选:D.
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