Answer:
f(x) = 6 when x = -3
Explanation:
Looking at the problem, it gives you two scenarios to get f(x):
1) When x is less than 0, multiply x by -2.
2) When x is greater than or equal to 0, multiply x by 4.
As defined by the question, x = -3. Since -3 is less than 0, you would go to scenario 1, which multiplies x (-3) by -2, giving you 6.