题目内容
(1)计算:(-1)2008-(
)-2+
-cos60°;
(2)课堂上,李老师出了这样一道题,已知x=2008-5
,求代数式
÷(1+
)的值,小明觉得直接代入计算太繁了,请你来帮他解决,并写出具体过程.
| 1 |
| 2 |
| 16 |
(2)课堂上,李老师出了这样一道题,已知x=2008-5
| 3 |
| x2-2x+1 |
| x2-1 |
| x-3 |
| x+1 |
(1)原式=1-4+4-0.5=0.5;
(2)原式=
÷(
+
)
=
÷
=
•
=
.
(2)原式=
| (x-1)2 |
| (x+1)(x-1) |
| x+1 |
| x+1 |
| x-3 |
| x+1 |
=
| x-1 |
| x+1 |
| 2(x-1) |
| x+1 |
=
| x-1 |
| x+1 |
| x+1 |
| 2(x-1) |
| 1 |
| 2 |
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