Réponse :
Explications étape par étape :
a.28/52 = 28/4//52/4 = 7/13 ou 28/52 = 28/2//52/2 = 14/2//26/2 = 7/13
b.75/60 = 75/5//60/5 = 15/3//12/3 = 5/4
c.242/66 = 242/11//66/11 = 22/2//6/2 = 11/3