1) ..........=7 9/12 - 4 10/12+3 6/12+1 8/12=7 13/12=8 1/12
2) .........=9 24/60 - 8 20/60+7 15/60 - 5 10/60=3 9/60=3 3/20
3) .........=6 15/24 - 12/24 - 5 18/24+2 4/24+9 15/24 - 7 8/24= 4 5/6
4) .........=5 2/60 - 2 36/60 - 8/60+6-7+6 55/60 - 15/60=7 29/30