Réponse :
Bonsoir
Explications étape par étape
A = -3/5 +9/20
A = -3/5 X 4/4 +9/20
A = -12/20 +9/20
A = -3/20
B = 5/12 -3/8
B = 5/12 X 8/8 -3/8 X 12/12
B = 40/96 -36/96
B = 4/96
B = 1/24
C = -2 - -4/3
C = -2 X 3/3 +4/3
C = -6/3 +4/3
C = -2/3
