Bonjour

1)

a. 5/9 + 3/9 = (5 + 3) / 9 = 8/9

b. 3/7 - 1/7 = (3 - 1) / 7 = 2/7

c. 3/14 + 1/14 + 5/14 = (3 + 1 + 5) / 14 = 9/14

d. 6/17 + 4/17 = (6 + 4) / 17 = 10/17

2)

a. 7/9 + 5/9 = 12/9 = (3 x 4) / (3 x 3) = 4/3

b. 19/8 - 15/8 = 4/8 = (4 x 1) / (4 x 2) = 1/2

c. 5/12 + 13/12 = 18/12 = (6 x 3) / (6 x 2) = 3/2

d. 9/11 + 7/11 = 16/11

e. 7/18 + 11/18 = 18/18 = 1

f. 27/13 - 1/13 = 26/13 = (13 x 2) / (13 x 1) = 2.