J) s.v.p trouver la fraction manquante

c) 3/4 x 7/4 = 12/28 = 4 x  3 / 4 x 7 = 3/7

f) 6/11 : 3/4 = 6/11 x 4/3 = 24/33 = 3 x 8 / 3 x 11 = 8/11

i) - 7/12 : 1/2 = - 7/12 x 2/1 = -14/12 = 2 x - 7 / 2 x 6 = - 7/6

l) 6/11 x 5/12 = 30/132 = 6 x 5 / 6 x 22 = 5/22

Ce que tu as fait est bon