Answer :
To find [tex]\( f(3) \)[/tex] for the function [tex]\( f(x) = -5x^2 - x + 20 \)[/tex], we need to substitute 3 for [tex]\( x \)[/tex] in the function and then simplify.
Here's how you can do it step-by-step:
1. Substitute 3 into the function:
[tex]\[
f(3) = -5(3)^2 - (3) + 20
\][/tex]
2. Calculate [tex]\( 3^2 \)[/tex]:
[tex]\[
3^2 = 9
\][/tex]
3. Multiply by -5:
[tex]\[
-5 \times 9 = -45
\][/tex]
4. Substitute into the function:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
5. Perform the addition and subtraction:
[tex]\[
-45 - 3 = -48
\][/tex]
[tex]\[
-48 + 20 = -28
\][/tex]
So, the value of [tex]\( f(3) \)[/tex] is [tex]\(-28\)[/tex].
Here's how you can do it step-by-step:
1. Substitute 3 into the function:
[tex]\[
f(3) = -5(3)^2 - (3) + 20
\][/tex]
2. Calculate [tex]\( 3^2 \)[/tex]:
[tex]\[
3^2 = 9
\][/tex]
3. Multiply by -5:
[tex]\[
-5 \times 9 = -45
\][/tex]
4. Substitute into the function:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
5. Perform the addition and subtraction:
[tex]\[
-45 - 3 = -48
\][/tex]
[tex]\[
-48 + 20 = -28
\][/tex]
So, the value of [tex]\( f(3) \)[/tex] is [tex]\(-28\)[/tex].
