题目内容
求未知数
![]() ![]() | X-![]() |
解:(1)
:18%=
,
:18%=6.5:x,
x=18%×6.5,
x×
=1.17×
,
x=7.8;
(2)x-
x=6,
x=6,
x×
=6×
,
x=8.
分析:(1)先利用比例的基本性质得出:
x=18%×6.5,再利用等式的性质,两边同时乘
即可解答;
(2)先把左边计算出来得:
x=6,再利用等式的性质两边同时乘
即可.
点评:此题主要考查比例的基本性质和等式的性质的灵活应用.
![](http://thumb.1010pic.com/pic5/latex/3856.png)
![](http://thumb.1010pic.com/pic5/latex/204572.png)
![](http://thumb.1010pic.com/pic5/latex/3856.png)
![](http://thumb.1010pic.com/pic5/latex/3856.png)
![](http://thumb.1010pic.com/pic5/latex/3856.png)
![](http://thumb.1010pic.com/pic5/latex/1883.png)
![](http://thumb.1010pic.com/pic5/latex/1883.png)
x=7.8;
(2)x-
![](http://thumb.1010pic.com/pic5/latex/96.png)
![](http://thumb.1010pic.com/pic5/latex/365.png)
![](http://thumb.1010pic.com/pic5/latex/365.png)
![](http://thumb.1010pic.com/pic5/latex/304.png)
![](http://thumb.1010pic.com/pic5/latex/304.png)
x=8.
分析:(1)先利用比例的基本性质得出:
![](http://thumb.1010pic.com/pic5/latex/3856.png)
![](http://thumb.1010pic.com/pic5/latex/1883.png)
(2)先把左边计算出来得:
![](http://thumb.1010pic.com/pic5/latex/365.png)
![](http://thumb.1010pic.com/pic5/latex/304.png)
点评:此题主要考查比例的基本性质和等式的性质的灵活应用.
![](http://thumb2018.1010pic.com/images/loading.gif)
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