Bonjours , Exercice 57 et 58 svp merci d'avance :)

Exercice 57
a) 5/7 /15/8 = 5/7 X 8/15 = 40/105 = 8/21
b) -4/25 /7/15 = -4/25 X 15/7 = -60/175 = -12/35
c) 24/6 /(-9/11) = 24/6 X 11/-9 = 264/-54= 132/27
d= -11/-18 / -8/15 = +11/18 X 15/-8= 165/-120 = 33/24
e= 18/-3/5 = 18 X 5/-3 = 90/-3=30
f = -21/28 / 4/9 = -21/28 X 9/4 = -189/112 

Exercice 58
2/9 /7/27 = 2/9 X 27/7 = 54/ 63 = 6/7
2/3 /-1/3 = 2/3 X 3/-1 = 6/-3 = -2
-3/15 / 15 = -3/15 X 1/15 = -3/225 = -1/75
-7/6 / -4/15 = -7/6 X 15/-4 = -105/-24 = + 35/8