Answer :
To find [tex]\( f(3) \)[/tex] for the function [tex]\( f(x) = -5x^2 - x + 20 \)[/tex], follow these steps:
1. Substitute 3 for [tex]\( x \)[/tex] in the function:
Start with the function:
[tex]\[
f(x) = -5x^2 - x + 20
\][/tex]
Replace [tex]\( x \)[/tex] with 3:
[tex]\[
f(3) = -5(3)^2 - 3 + 20
\][/tex]
2. Calculate the square and multiply:
First, calculate [tex]\( 3^2 \)[/tex]:
[tex]\[
3^2 = 9
\][/tex]
Now, multiply by -5:
[tex]\[
-5 \times 9 = -45
\][/tex]
3. Substitute back and simplify further:
Replace in the expression:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
Simplify by adding and subtracting the remaining numbers:
[tex]\[
f(3) = (-45 - 3) + 20
\][/tex]
[tex]\[
f(3) = -48 + 20
\][/tex]
[tex]\[
f(3) = -28
\][/tex]
So, the value of [tex]\( f(3) \)[/tex] is [tex]\(-28\)[/tex].
1. Substitute 3 for [tex]\( x \)[/tex] in the function:
Start with the function:
[tex]\[
f(x) = -5x^2 - x + 20
\][/tex]
Replace [tex]\( x \)[/tex] with 3:
[tex]\[
f(3) = -5(3)^2 - 3 + 20
\][/tex]
2. Calculate the square and multiply:
First, calculate [tex]\( 3^2 \)[/tex]:
[tex]\[
3^2 = 9
\][/tex]
Now, multiply by -5:
[tex]\[
-5 \times 9 = -45
\][/tex]
3. Substitute back and simplify further:
Replace in the expression:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
Simplify by adding and subtracting the remaining numbers:
[tex]\[
f(3) = (-45 - 3) + 20
\][/tex]
[tex]\[
f(3) = -48 + 20
\][/tex]
[tex]\[
f(3) = -28
\][/tex]
So, the value of [tex]\( f(3) \)[/tex] is [tex]\(-28\)[/tex].
