问题 解答题
求未知数x
4
5
x+200×25%=146
0.25:
5
8
=x:
4
9
0.75x+2.25x=21.
答案

(1)

4
5
x+200×25%=146,

4
5
x+50=146,

4
5
x+50-50=146-50,

4
5
x=96,

4
5
4
5
=96÷
4
5

x=120;

(2)0.25:

5
8
=x:
4
9

5
8
x=0.25×
4
9

5
8
x=
1
9

5
8
5
8
=
1
9
÷
5
8

x=

8
45

(3)0.75x+2.25x=21,

3x=21,

3x÷3=21÷3,

x=7.

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