Question

20/17-(12/5+20/7) 9/2+6/5-(6/5-9/4) 12/7-4/1-8/1+12/5 23/13-13/9+23/10+13/9简便计算

十二分之十一-七分之五+十二分之一-七分之二
上面的给写反了 应该是 / 前后反一下的

Answer 1

17/20-(5/12+7/20)
=17/20-5/12-7/20
=17/20-7/20-5/12
=10/20-5/12
=1/2-5/12
=6/12-5/12
=1/12

2/9+5/6-(5/6-4/9)
=2/9+5/6-5/6+4/9
=2/9+4/9
=6/9
=2/3

7/12-1/4-1/8+5/12
=1-1/4-1/8
=8/8-2/8-1/8
=(8-2-1)/8
=5/8

13/23-9/13+10/23+9/13
=13/23+10/23
=23/23
=1

11/12-5/7+1/12-2/7
=(11/12+1/12)-(5/7+2/7)
=1-1
=0