问题 解答题
解比例.
21
X
=
32
8
1
20
1
5
=X:
1
4
3.2
X
=0.5.
答案

(1)

21
x
=
32
8

         32x=21×8,

           x=

21×8
32

           x=

21
4

(2)

1
20
1
5
=x:
1
4

         

1
5
x=
1
20
×
1
4

         

1
5
x=
1
80

            x=

1
80
÷
1
5

            x=

1
16

(2)

3.2
x
=0.5,

     0.5x=3.2,

        x=3.2÷0.5,

        x=6.4

单项选择题
单项选择题