几道简单脱式计算3/4+1/3-1/2=?5/7-1/4-1/28=?4/5-(4/15+1/3)=?1-(3/20+2/3)=?1/2-3/8+1/4+?(3/5+5/8)-(3/5+5/8)-(3/5-3/8)=?

问题描述:

几道简单脱式计算
3/4+1/3-1/2=?
5/7-1/4-1/28=?
4/5-(4/15+1/3)=?
1-(3/20+2/3)=?
1/2-3/8+1/4+?
(3/5+5/8)-(3/5+5/8)-(3/5-3/8)=?

3/4+1/3-1/2=7/12
5/7-1/4-1/28=3/7
4/5-(4/15+1/3)=1/5
1-(3/20+2/3)=11/60
1/2-3/8+1/4=3/8
(3/5+5/8)-(3/5+5/8)-(3/5-3/8)=-9/40