题目内容
下列各题怎样计算简便就怎样算.
![数学公式](http://thumb.1010pic.com/pic5/latex/463997.png)
![数学公式](http://thumb.1010pic.com/pic5/latex/308291.png)
![数学公式](http://thumb.1010pic.com/pic5/latex/463998.png)
.
解:(1)
-
+![](http://thumb.1010pic.com/pic5/latex/63.png)
=
+
,
=
;
(2)6-(
-
)
=6-
,
=5
;
(3)
+
-
+
,
=
-
+(
+
),
=
+1,
=1
;
(4)
-(
+
)
=
-
,
=
.
分析:(1)按从左到右的顺序先算减法再算加法;
(2)(4)先算括号里面的,再算括号外的减法;
(3)可根据加法交换律与结合律计算.
点评:完成本题要细心,注意通分约分.
![](http://thumb.1010pic.com/pic5/latex/602.png)
![](http://thumb.1010pic.com/pic5/latex/28603.png)
![](http://thumb.1010pic.com/pic5/latex/63.png)
=
![](http://thumb.1010pic.com/pic5/latex/2132.png)
![](http://thumb.1010pic.com/pic5/latex/63.png)
=
![](http://thumb.1010pic.com/pic5/latex/7.png)
(2)6-(
![](http://thumb.1010pic.com/pic5/latex/365.png)
![](http://thumb.1010pic.com/pic5/latex/335.png)
=6-
![](http://thumb.1010pic.com/pic5/latex/5193.png)
=5
![](http://thumb.1010pic.com/pic5/latex/28483.png)
(3)
![](http://thumb.1010pic.com/pic5/latex/4458.png)
![](http://thumb.1010pic.com/pic5/latex/1207.png)
![](http://thumb.1010pic.com/pic5/latex/1154.png)
![](http://thumb.1010pic.com/pic5/latex/112.png)
=
![](http://thumb.1010pic.com/pic5/latex/4458.png)
![](http://thumb.1010pic.com/pic5/latex/1154.png)
![](http://thumb.1010pic.com/pic5/latex/1207.png)
![](http://thumb.1010pic.com/pic5/latex/112.png)
=
![](http://thumb.1010pic.com/pic5/latex/847.png)
=1
![](http://thumb.1010pic.com/pic5/latex/847.png)
(4)
![](http://thumb.1010pic.com/pic5/latex/602.png)
![](http://thumb.1010pic.com/pic5/latex/4457.png)
![](http://thumb.1010pic.com/pic5/latex/8.png)
=
![](http://thumb.1010pic.com/pic5/latex/602.png)
![](http://thumb.1010pic.com/pic5/latex/2131.png)
=
![](http://thumb.1010pic.com/pic5/latex/8.png)
分析:(1)按从左到右的顺序先算减法再算加法;
(2)(4)先算括号里面的,再算括号外的减法;
(3)可根据加法交换律与结合律计算.
点评:完成本题要细心,注意通分约分.
![](http://thumb2018.1010pic.com/images/loading.gif)
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