Bonjour, voici la réponse à tes exercices :
Exercice n°3
1. 5/6 + 3/14 = (5 × 7) / (6 × 7) + (3 × 3) / (14 × 3) = 35/42 + 9/42 = 44/42
2. 44/42 = (22 × 2) / (21 × 2) = 22/21
Exercice n°4
a. 1/2 + 7/5
= (1 × 5) / (2 × 5) + (7 × 2) / (5 × 2)
= 5/10 + 14/10
= 19/10
b. 8/7 - 7/12
= (8 × 12) / (7 × 12) - (7 × 7) / (12 × 7)
= 96/84 - 49/84
= 47/84
c. 2/23 - 11/10
= (2 × 10) / (23 × 10) - (11 × 23) / (10 × 23)
= 20/230 - 253/230
= - 233/230
d. - 3/4 - 7/9
= - (3 × 9) / (4 × 9) - (7 × 4) / (9 × 4)
= - 27/36 - 28/36
= (- 27 - 28) / 36
= - 55/36
En espérant t'avoir aidé au maximum !
