Répondre :
A : 1/3-1/3*4/7 = 1/3-4/21 = 7/21-4/21 = 3/21 = 1/7
B : 6/5 : 1/15-1/5 = 6/5:1/15-3/15 = 6/5:-2/15 = 6/5*(-15/2) = 3*2*5*5/5*2 = 3*5 = 15.
B : 6/5 : 1/15-1/5 = 6/5:1/15-3/15 = 6/5:-2/15 = 6/5*(-15/2) = 3*2*5*5/5*2 = 3*5 = 15.