Réponse :
bonsoir
A = - 20/12 - 2/3
A = - 10/6 - 4/6 = - 14 /6 = - 7/3
B = - 5 /20 - 7/4
B = - 1 /4 - 7 /4
B = - 8/4 = - 2
C = 7 /9 - 56/12
C = 7/9 - 14/3
C = 7/9 - 42/9
C = - 35/9
D = - 2/9 - 25/45
D = - 2/9 - 5/9
D = - 7/9
Explications étape par étape