Bonjour !
a.
9/7 = (9*6)/(7*6) = 54/42
54/42 = 9/7 < 57/42
b.
-16/3 = (-64*4)/(3*4) = -48/12
-23/4 = (-23*3)/(4*3) = -69/12
-48/12 = -16/3 > -69/12 = 23/4
c.
-5/8 = (-5*3/(8*3) = -15/24
-15/24 = -5/8 > -19/24
d.
-7/5 = (-7*2)/(5*2) = -14/10
-3/2 = (-3*5)/(2*5) = -15/10
-14/10 = -7/5 > -15/10 = -3/2
e.
7/15 = (7*4)/(15*4) = 28/60
5/12 = (5*5)/(12*5) = 25/60
28/60 = 7/15 > 25/60 = 5/12
f.
7/12 = (7*3)/(12*3) = 21/36
7/9 = (7*4)/(9*4) = 28/36
21/36 = 7/12 < 28/36 = 7/9
J'espère t'avoir aidé. Bon courage !
