题目内容
解方程:
+x=![数学公式](http://thumb.1010pic.com/pic5/latex/365.png)
X-
+
=![数学公式](http://thumb.1010pic.com/pic5/latex/155.png)
x-(
+
)=![数学公式](http://thumb.1010pic.com/pic5/latex/5690.png)
4x-
=
.
解:(1)
+x=
,
+x-
=
-
,
x=
;
(2)X-
+
=
,
X-(
-
)=
,
X-
=
,
X-
+
=
+
,
X=1;
(3)x-(
+
)=
,
x-
=
,
x-
+
=
+
,
x=
;
(4)4x-
=
,
4x-
+
=
+
,
4x=1,
4x÷4=1÷4,
x=
.
分析:(1)根据等式的性质,两边同减去
计算即可;
(2)运用减法的性质,把原式变为X-(
-
)=
,即X-
=
,根据等式的性质,两边同加上
即可;
(3)先求出
+
=
,根据等式的性质,两边同加上
即可;
(4)根据等式的性质,两边同加上
,再同除以4即可.
点评:此题考查了根据等式的性质解方程,即方程两边同加、同减、同乘或同除以某数(0除外),方程的左右两边仍相等;注意“=”号上下要对齐.
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/365.png)
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/365.png)
![](http://thumb.1010pic.com/pic5/latex/7.png)
x=
![](http://thumb.1010pic.com/pic5/latex/450.png)
(2)X-
![](http://thumb.1010pic.com/pic5/latex/8.png)
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/155.png)
X-(
![](http://thumb.1010pic.com/pic5/latex/8.png)
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/155.png)
X-
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/155.png)
X-
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/155.png)
![](http://thumb.1010pic.com/pic5/latex/7.png)
X=1;
(3)x-(
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/927.png)
![](http://thumb.1010pic.com/pic5/latex/5690.png)
x-
![](http://thumb.1010pic.com/pic5/latex/450.png)
![](http://thumb.1010pic.com/pic5/latex/5690.png)
x-
![](http://thumb.1010pic.com/pic5/latex/450.png)
![](http://thumb.1010pic.com/pic5/latex/450.png)
![](http://thumb.1010pic.com/pic5/latex/5690.png)
![](http://thumb.1010pic.com/pic5/latex/450.png)
x=
![](http://thumb.1010pic.com/pic5/latex/1207.png)
(4)4x-
![](http://thumb.1010pic.com/pic5/latex/597.png)
![](http://thumb.1010pic.com/pic5/latex/5192.png)
4x-
![](http://thumb.1010pic.com/pic5/latex/597.png)
![](http://thumb.1010pic.com/pic5/latex/597.png)
![](http://thumb.1010pic.com/pic5/latex/5192.png)
![](http://thumb.1010pic.com/pic5/latex/597.png)
4x=1,
4x÷4=1÷4,
x=
![](http://thumb.1010pic.com/pic5/latex/96.png)
分析:(1)根据等式的性质,两边同减去
![](http://thumb.1010pic.com/pic5/latex/7.png)
(2)运用减法的性质,把原式变为X-(
![](http://thumb.1010pic.com/pic5/latex/8.png)
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/155.png)
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/155.png)
![](http://thumb.1010pic.com/pic5/latex/7.png)
(3)先求出
![](http://thumb.1010pic.com/pic5/latex/7.png)
![](http://thumb.1010pic.com/pic5/latex/927.png)
![](http://thumb.1010pic.com/pic5/latex/450.png)
![](http://thumb.1010pic.com/pic5/latex/450.png)
(4)根据等式的性质,两边同加上
![](http://thumb.1010pic.com/pic5/latex/597.png)
点评:此题考查了根据等式的性质解方程,即方程两边同加、同减、同乘或同除以某数(0除外),方程的左右两边仍相等;注意“=”号上下要对齐.
![](http://thumb2018.1010pic.com/images/loading.gif)
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