Answer :
To evaluate the function
$$
f(x) = -5x^2 - x + 20
$$
at $x = 3$, follow these steps:
1. Substitute $x = 3$ into the function:
$$
f(3) = -5(3)^2 - 3 + 20.
$$
2. Calculate the square:
$$
3^2 = 9.
$$
3. Multiply by $-5$:
$$
-5 \times 9 = -45.
$$
4. Add the remaining terms:
$$
f(3) = -45 - 3 + 20.
$$
5. Simplify by combining the terms:
$$
-45 - 3 = -48,
$$
and then
$$
-48 + 20 = -28.
$$
Thus, the final result is
$$
f(3) = -28.
$$
$$
f(x) = -5x^2 - x + 20
$$
at $x = 3$, follow these steps:
1. Substitute $x = 3$ into the function:
$$
f(3) = -5(3)^2 - 3 + 20.
$$
2. Calculate the square:
$$
3^2 = 9.
$$
3. Multiply by $-5$:
$$
-5 \times 9 = -45.
$$
4. Add the remaining terms:
$$
f(3) = -45 - 3 + 20.
$$
5. Simplify by combining the terms:
$$
-45 - 3 = -48,
$$
and then
$$
-48 + 20 = -28.
$$
Thus, the final result is
$$
f(3) = -28.
$$
