要写出过程

来源：百度知道 编辑：UC知道 时间：2024/05/04 20:01:51
12/7+5/12-2/15
4/11+5/9+7/11+1/9
13/25-1/8-5/25
8/9-3/8-1/8

12/7+5/12-2/15
是不是7/12+5/12-2/15？
如果是则
7/12+5/12-2/15
=1-2/15
=13/15
如果不是则
12/7+5/12-2/15
=720/420+175/420-56/420
=839/420

4/11+5/9+7/11+1/9
=(4/11+7/11)+(5/9+1/9)
=1+2/3
=5/3

13/25-1/8-5/25
=(13/25-5/25)-1/8
=8/25-1/8
=64/200-25/200
=39/200

8/9-3/8-1/8
=8/9-(3/8+1/8)
=8/9-1/2
=16/18-9/18
=7/18