Réponse :
Bonsoir
Explications étape par étape :
A = 5/(-12) - ( - 1/3)
A = (-5/12) + 1/3
A = (-5/12) + 4/12
A = - 1/12
B = 4/3 - (-5/-4)
B = 4/3 - 5/4
B = 16/12 - 20/12
B = (- 4/12)
B = (-1/3)
C = (19/20) - (31/32)
C = (608/640) - (620/640)
C = (- 12/640)
C =(- 3/160)