Réponse :

bonjour

a = 2/3

b = 4/7

c = 5/3

d = 4/3

a = 3/2

b = 4/9

c =  3/7

d=  6/7

Explications étape par étape :

Bonjour

18)

a. 6/9 = (3 x 2) / (3 x 3) = 2/3

b. 8/14 = (2 x 4) / (2 x 7) = 4/7

c. 25/15 = (5 x 5) / (5 x 3) = 5/3

d. 16/12 = (4 x 4) / (4 x 3) = 4/3

19)

a. 21/14 = (7 x 3) / (7 x 2) = 3/2

b. 12/27 = (3  x 4) / (3 x 9) = 4/9

c. 36/42 = (6 x 6) / (6 x 7) = 6/7

d. 30/35 = (5 x 6) / (5 x 7) = 6/7.