ex 33 merci de laide!!

a) 1/2 + 1/4 = 1 x 2 / 2 x 2 + 1/4 = 2/4 + 1/4 = 3/4

b) 5/6 + 5/12 = 5 x 2 / 6 x 2 + 5/12 = 10/12 + 5/12 = 15/12 = 3 x 5 / 3 x 4 = 5/4

c) 13/14 + 5/7 = 13/14 + 5 x 2 / 7 x 2 = 13/14 + 10/14 = 23/14

d) 3/4 + 5/24 = 3 x 6 / 4 x 6 + 5/24 = 18/24 + 5/24 = 23/24

e) 6/7 + 2/35 = 6 x 5 / 7 x 5 + 2/35 = 30/35 + 2/35 = 32/35

f) 11/81 + 1/9 = 11/81 + 1 x 9 / 9 x 9 = 11/81 + 9/81 = 20/81