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