Bonjour !
a. -45/36 : 5/-9 = -45/36 * -9/5 = (-45*-9)/(36*5) = 405/180 = 9/4
b. -7/5 : 9/50 = -7/5 * 50/9 = (-7*50)/(5*9) = -350/45 = -70/9
c. 16/7 : -12/21 = 16/7 * 21/-12 = (16*21)/(7*-12) = 336/-84 = -4
d.-3/-4 : -5/-28 = -3/-4 * -28/-5 = (-3*-28)/(-4*-5) = 84/20 = 21/5
e. -11/8 : 33/12 = -11/8 * 12/33 = (-11*12)/(8*33) = -132/264 = -1/2
f. 7/2 : -3/4 = 7/2 * 4/-3 = (7*4)/(2*-3) = 28/-6 = -14/3
J'espère t'avoir aidé. Bon courage !
