题目内容
(1)计算:lg2+lg5-log![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_ST/0.png)
![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_ST/1.png)
![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_ST/2.png)
![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_ST/3.png)
![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_ST/4.png)
(2)化简:
![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_ST/5.png)
【答案】分析:(1)(2)利用指数幂和对数的运算性质即可算出.
解答:解:(1)原式=1![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_DA/0.png)
-
=1-3+
=-2;
(2)原式=
=
=
(a>0).
点评:熟练掌握指数幂和对数的运算性质是解题的关键.
解答:解:(1)原式=1
![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_DA/0.png)
![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_DA/1.png)
![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_DA/2.png)
![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_DA/3.png)
(2)原式=
![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_DA/4.png)
![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_DA/5.png)
![](http://thumb.zyjl.cn//pic6/res/gzsx/web/STSource/20131202113052030555877/SYS201312021130520305558018_DA/6.png)
点评:熟练掌握指数幂和对数的运算性质是解题的关键.
![](http://thumb.zyjl.cn/images/loading.gif)
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(1)计算:lg2+lg5-log