If f(a)=(a•a•a)-(a•a) + a-1 what is the value of f(-3)?

Answer:
-40
Step-by-step explanation:
f(a) = a³ - a² + a - 1
f(-3) = (-3)³ - (-3)² + (-3) - 1
f(-3) = (-27) - (9) + (-3) -1
f(-3) = -27 - 9 -3 - 1
f(-3) = -40