Answer :
To find the value of the function
$$
f(x) = -5x^2 - x + 20
$$
at $x = 3$, we substitute $3$ for $x$. Here are the detailed steps:
1. Substitute $x = 3$:
$$
f(3) = -5(3)^2 - (3) + 20
$$
2. Compute the square:
$$
(3)^2 = 9
$$
3. Multiply by $-5$:
$$
-5 \times 9 = -45
$$
4. Now substitute back into the equation:
$$
f(3) = -45 - 3 + 20
$$
5. Combine the terms:
$$
-45 - 3 = -48 \quad \text{and} \quad -48 + 20 = -28
$$
Thus, the final value is:
$$
f(3) = -28.
$$
Among the given options, the correct answer is $\boxed{-28}$.
$$
f(x) = -5x^2 - x + 20
$$
at $x = 3$, we substitute $3$ for $x$. Here are the detailed steps:
1. Substitute $x = 3$:
$$
f(3) = -5(3)^2 - (3) + 20
$$
2. Compute the square:
$$
(3)^2 = 9
$$
3. Multiply by $-5$:
$$
-5 \times 9 = -45
$$
4. Now substitute back into the equation:
$$
f(3) = -45 - 3 + 20
$$
5. Combine the terms:
$$
-45 - 3 = -48 \quad \text{and} \quad -48 + 20 = -28
$$
Thus, the final value is:
$$
f(3) = -28.
$$
Among the given options, the correct answer is $\boxed{-28}$.
