a. 2/6+5/6 = 7/6
b. 5/8-2/8 = 3/8
c. 7/9-12/9 = -5/9
a. 8/15+33/15 = 41/15
b. 20/24-7/24 = 13/24
c. 7/12-20/12 = -13/12