问题 解答题
解方程
x-0.25x=3x+
2
5
x=21
3.6x÷2=2.16.
答案

(1)x-0.25x=3,

(1-0.25)x=3,

0.75x=3,

0.75x÷0.75=3÷0.75,

x=4;

(2)x+

2
5
x=21,

(1+

2
5
)x=21,

1.4x=21,

1.4x÷1.4=21÷1.4,

x=15;

(3)3.6x÷2=2.16,

3.6x÷2×2=2.16×2,

3.6x=4.32,

3.6x÷3.6=4.32÷3.6,

x=1.2.

名词解释
单项选择题