简算:
5/11+5/7+6/11+2/7
=(5/11+6/11)+(5/7+2/7)
=11/11+7/7
=1+1
=2
只有分数没有运算符号,如果用加法应该是这样算
5/11十5/7十6/11十2/7
二(5/11十6/11)十(5/7十2/7)
=1十1
=2(用加法交换律和结合律)
6/11+5/7-5/11+1/11+2/7=6/11-5/11+1/11+(5/7+2/7)=2/11+1=1又2/11
5/11+5/7+6/11+2/7
=5/11+6/11+5/7+2/7
=1+1
=2
5/11-5/7+6/11-2/7
=5/11+6/11-5/7-2/7
=1-1
=0