Réponse :
Bonsoir
Explications étape par étape :
a) 8/5 + 3/7 = 56/35 + 24/35 = 80/35 = (16×5)/(7×5) = 16/7
b) - 7/9 + 5/12 = - 84/108 + 45/108 = - 39/108 = (3× -13)/(36×3) = - 13/36
c) 7/6 - 9/8 = 28/24 - 27/24 = 1/24
d) 1 + 2/9 = 9/9 + 2/9 = 11/9
e) 1 - 7/5 = 5/5 - 7/5 = - 2/5
f) 3 + 3/4 = 12/4 + 3/4 = 15/4
