问题 解答题
解方程
x-
3
5
x=36
42:
3
5
=x:
5
7
0.75
x
=
4.5
3
答案

(1)x-

3
5
x=36,

          

2
5
x=36,

       

2
5
x÷
2
5
=36÷
2
5

             x=90;

(2)42:

3
5
=x:
5
7

       

3
5
x=42×
5
7

    

3
5
x÷
3
5
=30÷
3
5

          x=50;

(3)

0.75
x
=
4.5
3

       4.5x=0.75×3,

  4.5x÷4.5=2.25÷4.5,

          x=0.5.

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