题目内容
脱式计算:
![]() ![]() ![]() ![]() | [1-(![]() ![]() | 19.8÷(3.45-1![]() |
解:
÷
-
×
,
=
×
-
,
=
,
=![](http://thumb.1010pic.com/pic5/latex/17871.png)
,
=
;
(2)[1-(
-
)]÷30%×40%,
=[1-(
)]×
×
,
=[1-
]×
,
=
×
,
=1.2;
(3)19.8÷(3.45-1
),
=19.8÷2.2,
=9.
分析:(1)含有两级运算先做乘除后做减法的顺序进行计算.
(2)、先计算中括号内部的再计算括号外面的.
(3)先计算小括号内部的,再就是括号外面的.
点评:本题按照四则混合运算的顺序进行计算,计算时要认真计算正确解答.
![](http://thumb.1010pic.com/pic5/latex/35.png)
![](http://thumb.1010pic.com/pic5/latex/5886.png)
![](http://thumb.1010pic.com/pic5/latex/96.png)
![](http://thumb.1010pic.com/pic5/latex/335.png)
=
![](http://thumb.1010pic.com/pic5/latex/35.png)
![](http://thumb.1010pic.com/pic5/latex/1412.png)
![](http://thumb.1010pic.com/pic5/latex/205703.png)
=
![](http://thumb.1010pic.com/pic5/latex/215441.png)
=
![](http://thumb.1010pic.com/pic5/latex/17871.png)
![](http://thumb.1010pic.com/pic5/latex/62050.png)
=
![](http://thumb.1010pic.com/pic5/latex/2405.png)
(2)[1-(
![](http://thumb.1010pic.com/pic5/latex/365.png)
![](http://thumb.1010pic.com/pic5/latex/28483.png)
=[1-(
![](http://thumb.1010pic.com/pic5/latex/517004.png)
![](http://thumb.1010pic.com/pic5/latex/395.png)
![](http://thumb.1010pic.com/pic5/latex/17871.png)
=[1-
![](http://thumb.1010pic.com/pic5/latex/63.png)
![](http://thumb.1010pic.com/pic5/latex/304.png)
=
![](http://thumb.1010pic.com/pic5/latex/2105.png)
![](http://thumb.1010pic.com/pic5/latex/304.png)
=1.2;
(3)19.8÷(3.45-1
![](http://thumb.1010pic.com/pic5/latex/96.png)
=19.8÷2.2,
=9.
分析:(1)含有两级运算先做乘除后做减法的顺序进行计算.
(2)、先计算中括号内部的再计算括号外面的.
(3)先计算小括号内部的,再就是括号外面的.
点评:本题按照四则混合运算的顺序进行计算,计算时要认真计算正确解答.
![](http://thumb2018.1010pic.com/images/loading.gif)
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