题目内容
(1)计算:(-1)2011+3×
-|1-
|+(3.14-π)0
(2)先化简,再求值:(
-
)-
,其中x=
-2.
| 1 | ||
|
| 3 |
(2)先化简,再求值:(
| 3x |
| x-1 |
| x |
| x+1 |
| x2-1 |
| x |
| 2 |
(1)(-1)2011+3×
-|1-
|+(3.14-π)0
=-1+
-
+1+1
=1;
(2)(
-
)•
=
•
=2x+4,
把x=
-2代入上式,
原式=2x+4=2
-4+4=2
.
| 1 | ||
|
| 3 |
=-1+
| 3 |
| 3 |
=1;
(2)(
| 3x |
| x-1 |
| x |
| x+1 |
| x2-1 |
| x |
=
| x(3x+3-x+1) |
| (x+1)(x-1) |
| (x+1)(x-1) |
| x |
=2x+4,
把x=
| 2 |
原式=2x+4=2
| 2 |
| 2 |
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