题干
已知函数f（x）=﹣（x﹣1）+log2
，则f（
）+f（﹣
）=____
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| x |
| 1 |
| + |
| x |
| 1 |
| x |
| 1 |
| + |
| x |
| 1 |
| x |
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| x |
答案(点此获取答案解析）
2
