7/8-(1/5+1/10)=7/8-3/10=35/40-12/40=23/40
5-3/7-4/7=5-(3/7+4/7)=5-1=4
4/3+7/10-1/3=4/3-1/3+7/10=1+7/10=1又7/10
5/6-(5/6-1/12)=5/6-5/6+1/12=1/12
4/3+7/10-1/3 5/6-(5/6-1/12) 7/8-(1/5+1/10) 5-3/7-4/7
=(4/3-1/3)+7/10 =5/6-5/6+1/12 =7/8-3/10 =5-(3/7+4/7)
=1+7/10 =1/12 = 23/40 =5-1
=17/10 =4