Unfortunately, you haven't shared the instructions for this problem. My guess is that you are to evaluate P(x)= x^3+4x^2-8x-6 for x = a = -2.
If that's the case, then
P(-2) = (-2)^3 + 4(-2)^2 - 8(-2) - 6. This simplifies to:
= -8 + 16 + 16 - 6 = 18 (answer)
