Réponse :
bonjour
A = 5/7 - 8 /21 = 15/21 - 8/21 = 7 /21 = 1 /3
B = 5 - 4/3 + 7/12 = 300/60 - 40/60 + 35/60 = 295/60 = 59/12
C = 3 - ( 13/15 - 2 /5) = 3 - ( 13/15 - 6/15) = 45/15 - 7 /15 = 38/15
D = 3/11 + 5/11 x 7/10 = 3 /11 + 35/110 = 30/110 + 35/100 = 65/110 = 13/22
Explications étape par étape
