Question

【题目】解方程。

1.8÷x=2 7x+15=15.7 4(x+0.4)=3.6

Answer 1

【答案】x =0.9 x =0.1 x =0.5

【解析】

1.8÷x=2

解：1.8÷x×x=2×x

2x =1.8

x =0.9

7x+15=15.7

解： 7x+15-15=15.7-15

7x=0.7

x =0.1

4(x+0.4)=3.6

解： 4(x+0.4)÷4=3.6÷4

x+0.4=0.9

x+0.4-0.4=0.9-0.4

x =0.5