题目内容
解方程.
x-
=
;
x+
=
;
+x+
=
.
解:(1)x-
=
,
x-
+
=
+
,
x=
;
(2)x+
=
;
x+
-
=
-
;
x=
;
(3)
+x+
=
,
+x+
-
=
-
,
x+
=1,
x+
-
=1-
,
x=
.
分析:(1)根据等式的性质,两边同加上
即可;
(2)根据等式的性质,两边同减去
即可;
(3)根据等式的性质,两边同减去
,再同减去
即可.
点评:在解方程时应根据等式的性质,即等式两边同加上、同减去或同乘上、同除以某一个数(0除外),等式的两边仍相等,同时注意等号上下要对齐.
![](http://thumb.1010pic.com/pic5/latex/597.png)
![](http://thumb.1010pic.com/pic5/latex/927.png)
x-
![](http://thumb.1010pic.com/pic5/latex/597.png)
![](http://thumb.1010pic.com/pic5/latex/597.png)
![](http://thumb.1010pic.com/pic5/latex/927.png)
![](http://thumb.1010pic.com/pic5/latex/597.png)
x=
![](http://thumb.1010pic.com/pic5/latex/14245.png)
(2)x+
![](http://thumb.1010pic.com/pic5/latex/36.png)
![](http://thumb.1010pic.com/pic5/latex/155.png)
x+
![](http://thumb.1010pic.com/pic5/latex/36.png)
![](http://thumb.1010pic.com/pic5/latex/36.png)
![](http://thumb.1010pic.com/pic5/latex/155.png)
![](http://thumb.1010pic.com/pic5/latex/36.png)
x=
![](http://thumb.1010pic.com/pic5/latex/204543.png)
(3)
![](http://thumb.1010pic.com/pic5/latex/96.png)
![](http://thumb.1010pic.com/pic5/latex/9777.png)
![](http://thumb.1010pic.com/pic5/latex/1180.png)
![](http://thumb.1010pic.com/pic5/latex/96.png)
![](http://thumb.1010pic.com/pic5/latex/9777.png)
![](http://thumb.1010pic.com/pic5/latex/96.png)
![](http://thumb.1010pic.com/pic5/latex/1180.png)
![](http://thumb.1010pic.com/pic5/latex/96.png)
x+
![](http://thumb.1010pic.com/pic5/latex/9777.png)
x+
![](http://thumb.1010pic.com/pic5/latex/9777.png)
![](http://thumb.1010pic.com/pic5/latex/9777.png)
![](http://thumb.1010pic.com/pic5/latex/9777.png)
x=
![](http://thumb.1010pic.com/pic5/latex/847.png)
分析:(1)根据等式的性质,两边同加上
![](http://thumb.1010pic.com/pic5/latex/597.png)
(2)根据等式的性质,两边同减去
![](http://thumb.1010pic.com/pic5/latex/36.png)
(3)根据等式的性质,两边同减去
![](http://thumb.1010pic.com/pic5/latex/96.png)
![](http://thumb.1010pic.com/pic5/latex/9777.png)
点评:在解方程时应根据等式的性质,即等式两边同加上、同减去或同乘上、同除以某一个数(0除外),等式的两边仍相等,同时注意等号上下要对齐.
![](http://thumb2018.1010pic.com/images/loading.gif)
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