问题 解答题
解方程.
11.8-2x=4
4
5

0.5:
1
4
=
2
3
:x

5.25x-18=
3
4
x
答案

(1)11.8-2x=4

4
5

11.8-2x+2x=4

4
5
+2x,

2x+4

4
5
=11.8,

2x+4

4
5
-4
4
5
=11.8-4
4
5

2x=7,

2x÷2=7÷2,

x=3.5;

(2)0.5:

1
4
=
2
3
:x,

0.5x=

1
4
×
2
3

0.5x=

1
6

0.5x÷0.5=

1
6
÷0.5,

x=

1
3

(3)5.25x-18=

3
4
x,

5.25x-18-

3
4
x=
3
4
x-
3
4
x,

4.5x-18=0,

4.5x-18+18=0+18,

4.5x=18,

4.5x÷4.5=18÷4.5,

x=4.

综合
单项选择题