1) 24/72+85/5 = 1/3+17/1 = 1+17/3 = 18/3 = 6
2) 30/6+6/7 = 5/1+6/7 = 5+6/7= 11/7 = 1 4/7
3) 1 + 3/12 = 1+3/12 = 4/12 = 1/3
4) 8/5 + 5/7 = (3/5)*7 + (5/7)*5 = 21/35 + 25/35 = 46/35 = 1 11/35
5) 2/4 + 3/8 = 1/2+3/8 = 4/8+3/8 = 7/8
6) 9/10 + 6/1 = 9+6/10 = 15/10 = 3/2 = 1 1/2
7) 12/13 - 5/5 = 12/13-1 = 12+1/13 = 13/13 = 1
8) 34/52 - 8/13 = 17/26-8/13 = 17/26-16/26 = 1/26
9) 3/11-6/23 = 69/253-66/253 = 3/253
10) 1/2 - 3/6 = 1/2-1/2 = 0