Final answer:
To evaluate the function f(x) = -3x^2 - 20 at -9, substitute -9 for x: f(-9) = -3(-9)^2 - 20 = -263.
Step-by-step explanation:
To evaluate the function f(x) = -3x^2 - 20, we substitute -9 for x:
f(-9) = -3(-9)^2 - 20
= -3(81) - 20
= -243 - 20
= -263
Therefore, f(-9) = -263.