(1)24x(11/12-7/8) =24*11/12-24*7/8=22-21=1 (2)6-(3/7÷3/14+6/13)=6-(3/7*14/3+6/13)=6-(2+6/13)=6-2-6/13=3又7/13 (3)1-5/8÷25/8-3/10=1-5/8*8/25-3/10=1-1/5-3/10=1-(2/10+3/10)=1-1/2=1/2