如题所述
第1个回答 2012-12-08
解:=1/2-2/3+4/5-1/2-1/3
=(1/2-1/2)-(2/3+1/3)+4/5
=-1/5本回答被提问者和网友采纳
=(1/2-1/2)-(2/3+1/3)+4/5
=-1/5本回答被提问者和网友采纳
第2个回答 2012-12-08
解: 1/2+(-2/3)-(-4/5)+(-1/2)-(+1/3)
=1/2-2/3+4/5-1/2-1/3
=1/2-1/2+4/5-2/3-1/3
=0+4/5-1
=-1/5
=1/2-2/3+4/5-1/2-1/3
=1/2-1/2+4/5-2/3-1/3
=0+4/5-1
=-1/5