Answer:
x^4 - x^3 - 4x^2 - 3.
Step-by-step explanation:
(f - g)(x) = f(x) - g(x)
= x^4 - x^2 + 9 - (x^3 + 3x^2 + 12)
Distributing the negative over the parentheses:
= x^4 - x^2 + 9 - x^3 - 3x^2 - 12
Simplifying like terms:
= x^4 - x^3 - 4x^2 - 3. (answer).
