bonjour
f (5) = 2/3 ⇔ f (x) = 2 x /15
f ( 2/3) = 3 ⇔ f (x) = 9 x /2
f (x) = 120 x /2 = 60 x
f ( - 8) = 17 ⇔ f (x) = - 17 x / 8
