5/6-4/9+1/6-2/9
=5/6+1/6-4/9-2/9
=1-6/9
=3/9
=1/3
13/15-7/112/15+6/11
这个题你输错了吧
应该是 13/15-7/11+2/15+6/11
=13/15+2/15-7/11+6/11
=1-1/11
=10/11
7/15-1/4+8/15-3/4
=7/15+8/15-1/4-3/4
=1-1
=0
11/12-1/18+5/12-17/18
=11/12+5/12-1/18-17/18
=16/12-1
=4/12
=1/3
0.7+11/15-3/10+4/15
=7/10-3/10+11/15+4/15
=4/10+1
=1.4