Réponse :
Explications étape par étape
Bonsoir
A = 5/7 - 3/7 : 9/4
A = 5/7 - 3/7 x 4/9
A = 5/7 - 3/9 x 4/7
A = 5/7 - 1/3 x 4/7
A = 5/7 - 4/21
A = (5 x 3)/(7 x 3) - 4/21
A = 15/21 - 4/21
A = 11/21
B = (2 - 3/5)(3/7 - 11/14)
B = (10/5 - 3/5)(6/14 - 11/14)
B = 7/5 x (-5/14)
B = -5/5 x 7/14
B = -1 x 1/2
B = -1/2
C = (10 - 17 - 9)/(7 - 5 x 5)
C = (10 - 26)/(7 x 25)
C = (-16)/(175)
C = -16/175
