Réponse :
Bonjour
Explications étape par étape
A=5/3 X 4/7 -15/42
A = 20/21 -15/42
A = 20/21 X 2/2 -15/42
A = 40/42 -15/42
A = 25/42
B = 7/3 : 6/5+10
B = 7/3 X 5/6 +10
B = 35/18 +10 X 18/18
B = 35/18 +180/18
B = 215/18
C = 6/7/11/5
C = 6/7 X 5/11
C = 30/77
D =5/3 +4/5
D = 5/3 X 5/5 +4/5 X 3/3
D = 25/15 +12/15
D = 37/15