Bonjour !
a) 60/80 = 60÷10 / 80÷10 = 6/8
=> 6/8 = 6÷2/8÷2 = 3/4
b) 63/14 = 63÷7/14÷7 = 9/2
c) 36/12 = 36÷12 / 12÷12 = 3/1
d) 13/65 = 13÷13 / 65÷13 = 1/5
e) 48/42 = 48÷6 / 42÷6 = 8/7
f) 40//24 = 48÷8 / 24÷8 = 6/3 = 2
g) 28/24 = 28÷4 / 24÷4 = 7/6
h) 66/11 = 66÷11 / 11÷11 = 6
Bonne journée.