题目内容
化简比并求比值.
125:75 | 1.6:2.4 |
|
0.5:
|
分析:(1)根据比的基本性质作答,即比的前项和后项同时乘或除以一个数(0除外)比值不变;
(2)用比的前项除以后项即可求其比值.
(2)用比的前项除以后项即可求其比值.
解答:解:(1)125:75,
=(125÷25):(75÷25),
=5:3;
125:75,
=125÷75,
=
;
(2)1.6:2.4,
=(1.6÷0.8):(2.4÷0.8),
=2:3;
1.6:2.4,
=1.6÷2.4,
=
;
(3)
:1
,
=
:
,
=(
×20):(
×20),
=1:25;
:1
,
=
÷
,
=
×
,
=
;
(4)0.5:
,
=
:
,
=(
×12):(
×12),
=6:5;
0.5:
,
=
÷
,
=
×
,
=
.
=(125÷25):(75÷25),
=5:3;
125:75,
=125÷75,
=
5 |
3 |
(2)1.6:2.4,
=(1.6÷0.8):(2.4÷0.8),
=2:3;
1.6:2.4,
=1.6÷2.4,
=
2 |
3 |
(3)
1 |
20 |
1 |
4 |
=
1 |
20 |
5 |
4 |
=(
1 |
20 |
5 |
4 |
=1:25;
1 |
20 |
1 |
4 |
=
1 |
20 |
5 |
4 |
=
1 |
20 |
4 |
5 |
=
1 |
25 |
(4)0.5:
5 |
12 |
=
1 |
2 |
5 |
12 |
=(
1 |
2 |
5 |
12 |
=6:5;
0.5:
5 |
12 |
=
1 |
2 |
5 |
12 |
=
1 |
2 |
12 |
5 |
=
6 |
5 |
点评:注意化简比的结果是一个比,它的前项和后项都是整数,并且是互质数;而求比值的结果是一个商,可以是整数、小数或分数.

练习册系列答案
相关题目