4/5·10=... 5/8:1/4=... 6:9/10=... 3/5·5/7=... 1/2:3/8=... 4/7·7/8=... 12/13:6=... 3/4·8/9=... 7/12:1/3=... 3/8:3/4=... 6·2/3=... 3/5·