Answer :
We want to evaluate the function
[tex]$$
f(x) = -5x^2 - x + 20
$$[/tex]
at [tex]$x = 3$[/tex].
Step 1. Substitute [tex]$x=3$[/tex] into the function:
[tex]$$
f(3) = -5(3)^2 - 3 + 20.
$$[/tex]
Step 2. Calculate [tex]$(3)^2$[/tex]:
[tex]$$
(3)^2 = 9.
$$[/tex]
Step 3. Multiply by [tex]$-5$[/tex]:
[tex]$$
-5 \times 9 = -45.
$$[/tex]
Step 4. Substitute back into the equation:
[tex]$$
f(3) = -45 - 3 + 20.
$$[/tex]
Step 5. Perform the additions:
[tex]$$
-45 - 3 = -48,
$$[/tex]
so
[tex]$$
-48 + 20 = -28.
$$[/tex]
Thus, the final answer is:
[tex]$$
f(3) = -28.
$$[/tex]
[tex]$$
f(x) = -5x^2 - x + 20
$$[/tex]
at [tex]$x = 3$[/tex].
Step 1. Substitute [tex]$x=3$[/tex] into the function:
[tex]$$
f(3) = -5(3)^2 - 3 + 20.
$$[/tex]
Step 2. Calculate [tex]$(3)^2$[/tex]:
[tex]$$
(3)^2 = 9.
$$[/tex]
Step 3. Multiply by [tex]$-5$[/tex]:
[tex]$$
-5 \times 9 = -45.
$$[/tex]
Step 4. Substitute back into the equation:
[tex]$$
f(3) = -45 - 3 + 20.
$$[/tex]
Step 5. Perform the additions:
[tex]$$
-45 - 3 = -48,
$$[/tex]
so
[tex]$$
-48 + 20 = -28.
$$[/tex]
Thus, the final answer is:
[tex]$$
f(3) = -28.
$$[/tex]
