Exo de math n 64 j arrive pas !!

Exercice 64 :

a/ 2/3 = 4/6
    
b/  5/7=15/21

c/ 1/7=5/35

d/  3/8=30/80    

e/  22/7 = 110/35    

f/  17/7 = 51/21

g/ 1/2=12/24  

h/  9/39= 3 /13  

i /  12/9 = 4/3