题目内容
化简
-
的结果是
| x2+5x |
| x-1 |
| 2x2+4x |
| x2-x |
x+4
x+4
．分析：先通分，再把分子相加减即可．
解答：解：原式=
-
=
-
=
=
=
=x+4．
故答案为：x+4．
| x2+5x |
| x-1 |
| x(2x+4) |
| x(x-1) |
=
| x2+5x |
| x-1 |
| 2x+4 |
| x-1 |
=
| x2+5x-2x-4 |
| x-1 |
=
| x2+3x-4 |
| x-1 |
=
| (x-1)(x+4) |
| x-1 |
=x+4．
故答案为：x+4．
点评：本题考查的是分式的加减法，在解答此类问题时要注意通分及约分的灵活应用．
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