问题 解答题
(1)计算:(-
2
)0-(
1
3
)-1-|-
3
|+2sin60°

(2)先化简,再求值:已知x=
2
+1,求(
x+1
x2-x
-
x
x2-2x+1
)÷
1
x
的值.
答案

(1)原式=1-3-

3
+2×
3
2

=1-3-

3
+
3

=-2;

(2)原式=[

x+1
x(x-1)
-
x
(x-1)2
]•x

=

x2-1-x2
x(x-1)2
•x

=-

1
(x-1)2

当x=

2
+1时,原式=-
1
(
2
+1-1)2
=-
1
2

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