1) 2/7+1/7 = (1+2)/7 = 3/7
2) 9/14-5/14 = (9-5)/14 = 4/14
3) 5/6-1/6 = (5-1)/6 = 4/6 = 2/3
4) 5/9+2/9 = (5+2)/9 = 7/9
5) 13/20+11/20 = (13+11)/20 = 24/20 = 6/5 = 1 1/5 = 1.2
6) 17/32-15/32 = (17-15)/32 = 2/32 = 1/16
7) 41/100-33/100 = (41-33)/100 = 8/100 = 2/25 = 0.08
8) 8/99+2/99 = (8+2)/99 = 10/99