八分之七减去括号3/4-1/8括号怎样简便7/8-(3/4-1/8)=7/8+1/8-3/4=1-3/4=1
7/8-(3/4-1/8)=7/8-3/4+1/8=1-3/4=1/4
7/8-(3/4-1/8)=7/8-3/4+1/8=7/8+1/8-3/4=1-3/4=1/4