Bonsoir,

Exercice 1 :

15/21 = 15 ÷ 3 / 21 ÷ 3 = 5/7

10/14 = 10 ÷ 2 / 14 ÷ 2 = 5/7

30/48 = 30 ÷ 6 / 48 ÷ 6 = 5/8

3/21 = 3 ÷ 3 / 21 ÷ 3 = 1/7

40/75 = 40 ÷ 5 / 75 ÷ 5 = 8/15

34/28 = 34 ÷ 2 / 28 ÷ 2 = 17/14

Exercice 2 :

a) x = 4/7

7 × 4/7 = 4

b) x = 8/6 = 4/3

4/3 × 6 = 8

c) x = 33/15 = 11/5

15 × 11/5 = 33

d) x = 7/12

12 × 7/12 = 7

Réponse :

exercise2:

a: 7fois2moins10

b: 2fois6moins4

c: 15fois2plus3

d: 12fois1moins5