1 23/45:(3 2/5-1 2/15)=68/45:(17/5-17/15)=68/45:(51/15-17/15)=68/45:34/15=68/45*15/34=2/3
1 23/45:(3 2/5-1 2/15)
68/45:(17/5-17/15)
1)17/5-17/15=51/15-17/15=34/15
2)68/45:34/15=68/45*15/34=2/3