2/5=( )/15=14/( ) 14/21=2/( )=6/9 4/7=( )/21=20/( )=( )/42

问题描述:

2/5=( )/15=14/( ) 14/21=2/( )=6/9 4/7=( )/21=20/( )=( )/42

2/5=(6 )/15=14/( 35)
14/21=2/( 3)=6/9
4/7=( 12)/21=20/( 35)=( 24)/42