题目内容
化简分式:(x+
)2-[x+
-
]2÷
.
| 1 |
| x |
| 1 |
| x |
| 1 | ||
1-x-
|
x2+
| ||||
x2+
|
令
=a,则x2+
=(x+
)2-2=a2-2.
原式=a2-(a-
)2÷
=a2-(
)2÷
=a2-(a2-a+1)
=a-1
=x+
-1=
.
| x+1 |
| x |
| 1 |
| x2 |
| 1 |
| x |
原式=a2-(a-
| 1 |
| 1-a |
| a2-2-a+3 |
| a2-2-2a+3 |
=a2-(
| a2-a+1 |
| a-1 |
| a2-a+1 |
| (a-1)2 |
=a2-(a2-a+1)
=a-1
=x+
| 1 |
| x |
| x2-x+1 |
| x |
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