-|-2/3-(+2/3)|-|(-1/5)+(-2/5)| |4/7-2/5|-|3/5-7/9|+|2/9-3/7|

问题描述:

-|-2/3-(+2/3)|-|(-1/5)+(-2/5)| |4/7-2/5|-|3/5-7/9|+|2/9-3/7|

11/15

-|-2/3-(+2/3)|-|(-1/5)+(-2/5)|
=-|-2\3-2\3|-|-1\5-2\5|
=-|-4\3|-|-3\5|
=-4\3-3\5
=-29\15
|4/7-2/5|-|3/5-7/9|+|2/9-3/7|
=|6\35|-|-8\45|+|-13\63|
=6\35-8\45+13\63
=7\35

1:原式=-4/3-3/5=-29/15
2:原式=6/35-8/45+13/63
=1/5

-29/15