4/5-3/10+1/3
=8/10-3/10+1/3
=5/10+1/3
=1/2+1/3
=3/6+2/6
=5/6
6-（5/8-5/12）
=6-（15/24-10/24）
=6-5/24
=5又19/24
7/9-5/8-1/12
=112/144-90/144-12/144
=（112-90-12）/144
=10/144
=5/77
7/12-1/4-1/3
=7/12-3/12-4/12
=（7-3-4）/12
=0
3/5-1/4+2/5
=3/5+2/5-1/4
=1-1/4
=3/4
1/12+（5/6+3/10）
=1/12+5/6+3/10
=1/12+10/12+3/10
=11/12+3/10
=55/60+18/60
=73/60
=1又13/60
1-1/2-1/3
=6/6-3/6-2/6
=1/6
1-（1/4-1/8）-（1/8-1/16）-（1/16-1/32）-（1/32-1/64
=1-1/8-1/16-1/32-1/64
=1-（8+4+2+1）/64
=1-15/64
=49/64
8/17+（3/5-8/17）
=8/17+3/5-8/17
=3/5
5/8+4/9+3除8-4/9
=[（45+32)/72+3]÷（8-4/9）
=293/72÷68/9
=293/72×9/68
=293/544
3/7+4/9-3/7+5/9
=3/7-3/7+4/9+5/9
=1
7/24+5/19+14/19+3/24
=7/24+3/24+5/19+14/19
=10/24+1
=1又5/12
1-7/9=2/9
1/6+1/7=7/42+6/42=13/42
2/3+1/6=4/6+1/6=5/6