题目内容
解方程
(1)10.4-x=9
;
(2)x-
=
;
(3)x+
=
+
.
解:(1)10.4-x=
,
10.4-x+x=9.4+x,
9.4+x=10.4,
9.4-9.4+x=10.4-9.4,
x=1;
(2)x-
=
,
x-
+
=
+
,
x=
,
x=
;
(3)x+
=
+
,
x+
=
,
x+
-
=
-
,
x=
,
x=
.
分析:(1)根据数字特点,把
化成小数为9.4,根据等式性质,在方程两边同加上x,得到9.4+x=10.4,两边同减去9.4即可;
(2)根据等式性质,两边同加上
,计算即可;
(3)先把
算出来,再根据等式性质,两边同减去
即可.
点评:解方程时就是根据等式性质,方程两边通过加、减、乘或除以某数,使方程的左边只剩下X,即X=?,求出解.注意“=”号上下要对齐,解完方程后要在草纸上验算.
![](http://thumb.1010pic.com/pic5/latex/437276.png)
10.4-x+x=9.4+x,
9.4+x=10.4,
9.4-9.4+x=10.4-9.4,
x=1;
(2)x-
![](http://thumb.1010pic.com/pic5/latex/1154.png)
![](http://thumb.1010pic.com/pic5/latex/168.png)
x-
![](http://thumb.1010pic.com/pic5/latex/1154.png)
![](http://thumb.1010pic.com/pic5/latex/1154.png)
![](http://thumb.1010pic.com/pic5/latex/168.png)
![](http://thumb.1010pic.com/pic5/latex/1154.png)
x=
![](http://thumb.1010pic.com/pic5/latex/517014.png)
x=
![](http://thumb.1010pic.com/pic5/latex/213890.png)
(3)x+
![](http://thumb.1010pic.com/pic5/latex/8064.png)
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/602.png)
x+
![](http://thumb.1010pic.com/pic5/latex/8064.png)
![](http://thumb.1010pic.com/pic5/latex/143069.png)
x+
![](http://thumb.1010pic.com/pic5/latex/8064.png)
![](http://thumb.1010pic.com/pic5/latex/8064.png)
![](http://thumb.1010pic.com/pic5/latex/143069.png)
![](http://thumb.1010pic.com/pic5/latex/8064.png)
x=
![](http://thumb.1010pic.com/pic5/latex/517015.png)
x=
![](http://thumb.1010pic.com/pic5/latex/3660.png)
分析:(1)根据数字特点,把
![](http://thumb.1010pic.com/pic5/latex/437276.png)
(2)根据等式性质,两边同加上
![](http://thumb.1010pic.com/pic5/latex/1154.png)
(3)先把
![](http://thumb.1010pic.com/pic5/latex/582608.png)
![](http://thumb.1010pic.com/pic5/latex/8064.png)
点评:解方程时就是根据等式性质,方程两边通过加、减、乘或除以某数,使方程的左边只剩下X,即X=?,求出解.注意“=”号上下要对齐,解完方程后要在草纸上验算.
![](http://thumb2018.1010pic.com/images/loading.gif)
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