简便计算
7/8-(1/6+1/8)
=7/8-1/8-1/6
=3/4-1/6
=7/12
1/4+7/9+3/4-2/9
=(1/4+3/4)+(7/9-2/9)
=1+5/9
=1又5/9
将相同分母的先算
7/8-(1/6+1/8)
=7/8-1/6-1/8
=7/8-1/8-1/6
=6/8-1/6
=3/4-1/6
=9/12-2/12
=7/12
1/4+7/9+3/4-2/9
=(1/4+3/4)+(7/9-2/9)
=1又5/9
=7/8-1/6-1/8
=6/8-1/6
=18/24-4/24
=7/12
=1/4+3/4+(7/9-2/9)
=1+5/9
=14/9
7/8-(1/6+1/8)=7/8-1/8-1/6=6/8-1/6
=3/4-1/6=9/12-2/12=7/12
1/4+7/9+3/4-2/9=(1/4+3/4)+(7/9-2/9)
=1+5/9=1又5/9
7/8-(1/6+1/8)
=7/8-1/6-1/8
=7/8-1/8-1/6
=6/8-1/6
=18/24-4/24
=7/12
1/4+7/9+3/4-2/9
=(1/4+3/4)+(7/9-2/9)
=1+5/9
=14/9