Réponse:

Exercice 2 :

A= 8/12 + 5/3

A= 2/3 + 5/3

A= 7/3

B= 40/72 - 1/9

B= 5/9 - 1/9

B= 4/9

C= 15/35 + 2/7

C= 3/7 + 2/7

C= 5/7

D= 5/3 - 52/39

D= 5/3 - 4/3

D= 1/3

Exercice 3 :

A= 13/8 + 5/2 +3/4

A= 13/8 + 20/8 + 6/8

A= 39/8

B= 5/12 + 11/24 + 1/6

B= 10/24 + 11/24 + 4/24

B= 25/24

C= 2 + 3/7 + 11/14

C= 28/14 + 6/14 + 11/14

C= 45/14

D= 3/5 - 4/15 - 7/30

D= 18/30 - 8/30 - 7/30

D= 3/30

D= 1/10

E= 14/9 + 2/3 - 5/18

E= 28/18 + 12/18 - 5/18

E= 35/18

F= 1 - 9/34 + 3/2

F= 34/34 - 9/34 + 51/34

F= 76/34

F= 38/17