Bonjour,
G = 6/5 x ( 25/18 - 5/6)
G = 6/5 x (25/18 - 5 x 3 / 6 x 3)
G = 6/5 x (25/18 - 15/18)
G = 6/5 x 10/18
G = 60/90
G = 30 x 2 / 30 x 3
G = 2/3
G = 6/5 x (25/18 - 5/6)
G = 6/5 x 25/18
G = 150/90
G = 30 x 5 / 30 x 3
G = 5/3
et
G = 6/5 x - 5/6
G = - 30/30
G = - 1
5/3 - 1 = 5/3 - 3/3 = 2/3