hey
ex 5
x 3 -5
f(x) 12
1) fonction linéaire = situation de proportionnalité => tableau de proportionnalité
2) le coef a = 12/3 = 4 (voir 1ere colonne)
3) si a = 4 => f(x) = 4x
4) f(-5) = 4 * (-5) = ...
ex 6
f(x) = -4x = -4 * x
f(3) = -4 * 3 = -12
f(-5) = .. tu as compris
f(7/12) = .. tu as compris
