题目内容
先化简,再求值:(1+
)÷
,其中:x=-2.
| 1 |
| x-1 |
| x |
| x2-1 |
(1+
)÷
,
=
×
,
=
×
,
=x+1,
当x=-2时,
原式=-2+1,
=-1.
| 1 |
| x-1 |
| x |
| x2-1 |
=
| x-1+1 |
| x-1 |
| (x-1)(x+1) |
| x |
=
| x |
| x-1 |
| (x-1)(x+1) |
| x |
=x+1,
当x=-2时,
原式=-2+1,
=-1.
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