Bonjour
a. - 3/8 : 6/16 = - 3/8 x 16/6 = - 48/48 = - 1
b. 15/12 : - 5/- 12 = 15/12 x 12/5 = 180/60 = (60 x 3) / (60 x 1) = 3
c. - 14/25 : - 7/15 = - 14/25 x - 15/7 = 210/175 = (35 x 6) / (35 x 5) = 6/5
d. 5/11 : 15/66 = 5/11 x 66/15 = 330/165 = (165 x 2) / (165 x 1) = 2.