1целая 1 \5 + 3 целых 19\30 ,- 4 целых 23\42

1 1/5+ 3 19/30- 4 23/42=2/7 .

1)) 1 1/5+ 3 19/30= 1 (1•6)/(5•6)+ 3 19/30=

1 6/30+ 3 19/30= 4 25/30= 4 5/6.

2)) 4 5/6- 4 23/42=
4 (5•7)/(6•7) - 4 23/42= 4 35/42- 4 23/42= 12/42= 6/21= 2/7.