Выполните действия :1) 4/5 - 3/10 2) 1/12+1/10 3) 9/20 - 1/30

1)4/5-3/10=8/10-3/10=5/10..........2)1/12+1/10=5/60+6/60=11/60..........3)9/20-1/30=27/60-2/60=25/60