Réponse:

bonjour,

Exercice 1

A) 4/9 - 7/27 =

(3 × 4)/(3 × 9) - (1 × 7)/(1 × 27) =

12/27 - 7/27 =

(12 - 7)/27 =

5/27

B) 6/5 - 8/45 =

(6×9 )/ (5×9) - 8/45 =

54/45 -8/45 =

46/45

C) 6/5 - 7/30 =

(6×6)/(5×6) - 7/30 =

36/30 - 7/30 =

29/30

D) 8/7 - 4/35 =

(8×5)/(7×5) - 4/35 =

45/35 - 4/35 =

41/35

E) 10/9 - 5/72 =

(10×8)/(9×8) - 5/72 =

80/72 - 5/72 =

75/72

F) 9/14 + 3/2 =

9/14 + (3×7)/(7×2) =

9/14 + 21/14 =

30/14

G) 10/7 - 4/35 =

(10×5)/(7×5) - 4/35 =

50/35 - 4/35 =

46/35

H) 10/49 + 8/7 =

10/49 + (8×7)/(7×7) =

10/49 + 54/49 =

64/49

Tous les autre exercices sont les mêmes que le premier, tu as plus qu'à faire de même pour les autres