Bonjour,

Exercice 15

7/11 = 14/22 ( on multiplie par2)

12/5 = 72/30 ( par 6)

9/7 = 81/63 (par 9)

13/2 = 65/10 (par 5)

Exercice 18

6/9 = 2/3 ( on divise par 3)

8/14 = 4/7

25/15 =  5/3

16/12 = 8/6 = 4/3

exercice 14

a. 3/4 9/12

b. 4/5 = 20/25

c. 2/7 = 6/21

d. 6/5 = 24/20

Exercice 15

7/11 = 14/22

12/5 = 72/30

9/7 = 81/63

13/2 = 65/10

exercice 16

a. 7/11 = 14/22

b. 12/5 = 72/30

c. 81/63 = 9/7

d. 65/10 = 13/2

exercice 16

a. 32/36 = 8/9

b. 70/77 = 10/11

c. 36/42 = 6/7

d. 81/72 = 9/8

exercice 18

a. 6/9 = 2/3

b. 8/14 = 4/7

c. 25/15 = 5/3

d. 16/12 = 8/6 = 4/3