问题 解答题
解比例或方程
5x+300=650

2.8x-2x=4
4x-3×18=104
1
4
:x=
1
8
1
10
答案

①5x+300=650,

5x+300-300=650-300,

5x=350,

5x÷5=350÷5,

x=70;

②2.8x-2x=4,

x(2.8-2)=4,

0.8x=4,

0.8x÷0.8=4÷0.8,

x=5;

③4x-3×18=104,

4x-54=104,

4x-54+54=104+54,

4x=158,

4x÷4=158÷4,

x=39.5;

1
4
:x=
1
8
1
10

1
8
x=
1
4
×
1
10

1
8
x=
1
40

1
8
1
8
=
1
40
÷
1
8

x=

1
5

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