问题 解答题
解方程.
3
8
-5x=0.125
x:0.2=
5
8
12X+7×0.3=20.1         
1
2
X+
1
3
X=1.2.
答案

(1)

3
8
-5x=0.125,

0.125+5x=

3
8

0.125+5x-0.125=

3
8
-0.125,

5x=0.25,

5x÷5=0.25÷5,

x=0.05;

(2)x:0.2=

5
8

x÷0.2=

5
8

x÷0.2×0.2=

5
8
×0.2,

x=0.125;

(3)12X+7×0.3=20.1,

12X+2.1=20.1,

12X+2.1-2.1=20.1-2.1,

12X=18,

12X÷12=18÷12,

X=1.5;

(4)

1
2
X+
1
3
X=1.2,

5
6
X=1.2,

5
6
5
6
=1.2÷
5
6

X=1.44.

单项选择题
单项选择题