Ci-joint se trouvent les calculs.
Réponse :
D = 3/5-1 = 3/5-5/5 = -2/5
E = 7-9/5 = 7/1-9/5 = 35/5-9/5 = 26/5
F = 12+8/3 = 12/1+8/3 = 36/3+8/3 = 44/3