解:①6x=0.42,
6x÷6=0.42÷6,
x=0.07;
②x-
![](http://thumb.1010pic.com/pic5/latex/14.png)
x=
![](http://thumb.1010pic.com/pic5/latex/15.png)
,
(1-
![](http://thumb.1010pic.com/pic5/latex/14.png)
)x=
![](http://thumb.1010pic.com/pic5/latex/15.png)
,
![](http://thumb.1010pic.com/pic5/latex/335.png)
x=
![](http://thumb.1010pic.com/pic5/latex/15.png)
,
![](http://thumb.1010pic.com/pic5/latex/335.png)
x×
![](http://thumb.1010pic.com/pic5/latex/259.png)
=
![](http://thumb.1010pic.com/pic5/latex/15.png)
×
![](http://thumb.1010pic.com/pic5/latex/259.png)
,
x=3;
③9:
![](http://thumb.1010pic.com/pic5/latex/365.png)
=x:
![](http://thumb.1010pic.com/pic5/latex/7.png)
,
![](http://thumb.1010pic.com/pic5/latex/365.png)
x=9×
![](http://thumb.1010pic.com/pic5/latex/7.png)
,
![](http://thumb.1010pic.com/pic5/latex/365.png)
x×
![](http://thumb.1010pic.com/pic5/latex/304.png)
=
![](http://thumb.1010pic.com/pic5/latex/33.png)
×
![](http://thumb.1010pic.com/pic5/latex/304.png)
,
x=2.
分析:①根据等式的性质,两边同除以6即可;
②运用乘法分配律改写成(1-
![](http://thumb.1010pic.com/pic5/latex/14.png)
)x=
![](http://thumb.1010pic.com/pic5/latex/15.png)
,即
![](http://thumb.1010pic.com/pic5/latex/335.png)
x=
![](http://thumb.1010pic.com/pic5/latex/15.png)
,根据等式的性质,两边同乘
![](http://thumb.1010pic.com/pic5/latex/259.png)
即可;
③先根据比例的性质改写成
![](http://thumb.1010pic.com/pic5/latex/365.png)
x=9×
![](http://thumb.1010pic.com/pic5/latex/7.png)
,再根据等式的性质,两边同乘
![](http://thumb.1010pic.com/pic5/latex/304.png)
即可.
点评:此题考查了根据等式的性质解方程,即等式两边同加、同减、同乘或同除以一个数(0除外),等式的左右两边仍相等;注意等号上下要对齐.