问题 解答题
解方程:
(1-
2
4
)x=14
37.5+20%x=69.5
x-
7
15
x=
14
25
答案

(1)(1-

2
4
)x=14,

              

1
2
x=14,

           

1
2
x×2=14×2,

                 x=28;

(2)37.5+20%x=69.5,

     37.5+0.2x=69.5,

37.5-37.5+0.2x=69.5-37.5,

          0.2x=32,

     0.2x÷0.2=32÷0.2,

             x=160;

(3)x-

7
15
x=
14
25

 (1-

7
15
)x=
14
25

      

8
15
x=
14
25

 

8
15
8
15
=
14
25
÷
8
15

          x=

14
25
×
15
8

          x=

21
20

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