7 5/12-1 3/6=7 5/12-1 6/12=6 17/12-1 6/12=5 11/12
2 5/12-1 12/24=2 10/24-1 12/24=1 34/24-1 12/24=22/24=11/12
12 2/10-4 5/6=12 6/30-4 25/30=11 36/30-4 25/30=7 11/30
8 8/12-6 2/18=8 24/36-6 4/36=2 20/36=4 5/9
3 1/3-2*(3/6-0,8)=3 14/15
3/6-4/5=15/30-24/30=-9/30=-3/10
-2*(-3/10)=3/5
3 1/3+3/5=3 5/15+9/15=3 14/15
4 1/4-(5/9+4)=-11/36
5/9+4=4 4/9
4 1/4-4 5/9=4 9/36-4 20/36=-11/36