1.甲数是8,是乙数的4/5,乙数是丙数的5/7,求丙数.2.3/5加上5/6与2/5的积,所得的和除以7/9,商是多少?
问题描述:
1.甲数是8,是乙数的4/5,乙数是丙数的5/7,求丙数.2.3/5加上5/6与2/5的积,所得的和除以7/9,商是多少?
答
丙数是8÷4/5÷5/7
=8*5/4*7/5
=14
2,(3/5+5/6*2/5)÷7/9
=(3/5+1/3)*9/7
=(9/15+5/15)*9/7
=14/15*9/7
=6/5