Réponse:

f(-3) = 21

f(0) = 3

f(1.5) = -6

Explications :

f(-3) = -6* (-3) +3 = 18 + 3 = 21

f(0) = -6* (0) +3 = 0 + 3 = 3

f(1.5) = -6* (1.5) +3 = -9 +3 = -6