第1个回答 2012-12-28
5/6-(1/3+3/10)
=5/6-1/3-3/10
=5/6-2/6-3/10
=1/2-3/10
=5/10-3/10
=1/5
8/9-4/15+3/5
=8/9-4/15+9/15
=8/9+1/3
=8/9+3/9
=12/9
=4/3
4/5-(3/4-2/3)
=4/5-3/4+2/3
=48/60-45/60+40/60
=43/60
5/12+7/8+7/12+5/8
=1+12/8
=7/3
4/9+5/6-4/9
=5/6
7/12+4/7+3/7
=7/12+1
=19/12