最后的得数我要分数
追答不简便:
3/5+1/3+2/5+7/12
解,得:
==3/5+2/5+7/12+4/12
==1+11/12
==23/12
13/15-(7/15-1/4)
解,得:
==13/15-7/15+1/4
==2/5+1/4
==0.4+0.25
==13/20
简便:
5/12+1/3+7/12+2/3
解,得:
==(5/12+7/12)+(2/3+1/3)
==1+1
==2
7/9-(4/9+1/3)
解,得:
==7/9-4/9-1/3
==1/3-1/3
==0