1
00:00:00,636 --> 00:00:04,158
我们现在来看一下分数的除法

2
00:00:04,436 --> 00:00:08,373
比如说我有负5/6

3
00:00:08,524 --> 00:00:15,988
除以3/4

4
00:00:15,988 --> 00:00:19,524
我们已经复习过除法

5
00:00:19,524 --> 00:00:22,936
这和乘以它的倒数是一样的

6
00:00:22,966 --> 00:00:32,516
所以，这和负5/6乘以3/4的倒数

7
00:00:32,516 --> 00:00:40,825
我只是把分子和分母倒一下

8
00:00:40,825 --> 00:00:47,076
我们已经谈过分数乘法，这次是分子相乘

9
00:00:47,076 --> 00:01:03,913
所以是-5乘以4。分母上是6乘以3

10
00:01:03,913 --> 00:01:09,936
现在分子上有一个负数。5乘以4是20

11
00:01:09,936 --> 00:01:13,528
你只要记住，现在是负数乘以正数

12
00:01:13,528 --> 00:01:21,002
这里其实有4个-5，等于-20

13
00:01:21,002 --> 00:01:27,139
所以分子是-20，分母是18

14
00:01:27,139 --> 00:01:30,315
答案是-20/18，但我们需要简化

15
00:01:30,315 --> 00:01:38,322
把分子和分母都除以2

16
00:01:38,322 --> 00:01:42,920
我们把分子和分母都除以2，来简化

17
00:01:42,920 --> 00:01:45,861
因为2是同时能被分子和分母除的数

18
00:01:45,892 --> 00:01:53,323
20除以2是10，18除以2是9

19
00:01:53,323 --> 00:02:02,220
所以5/6除以3/4。。

20
00:02:02,220 --> 00:02:07,464


21
00:02:07,464 --> 00:02:09,730


22
00:02:09,730 --> 00:02:24,327


23
00:02:24,327 --> 00:02:30,139


24
00:02:30,139 --> 00:02:36,726


25
00:02:36,726 --> 00:02:41,217


26
00:02:41,217 --> 00:02:45,138


27
00:02:45,138 --> 00:02:51,727


28
00:02:51,727 --> 00:02:56,817


29
00:02:56,817 --> 00:03:05,276


30
00:03:05,276 --> 00:03:08,260


31
00:03:08,260 --> 00:03:13,463


32
00:03:13,463 --> 00:03:19,224


33
00:03:19,224 --> 00:03:29,373


34
00:03:29,373 --> 00:03:34,996


35
00:03:34,996 --> 00:03:42,320


36
00:03:42,320 --> 00:04:00,260


37
00:04:00,260 --> 00:04:04,260