Answer :
To find [tex]\( f(3) \)[/tex] for the function [tex]\( f(x) = -5x^2 - x + 20 \)[/tex], follow these steps:
1. Substitute [tex]\( x = 3 \)[/tex] into the function:
[tex]\[
f(3) = -5(3)^2 - (3) + 20
\][/tex]
2. Calculate [tex]\( 3^2 \)[/tex]:
[tex]\[
3^2 = 9
\][/tex]
3. Substitute and multiply:
[tex]\[
f(3) = -5 \times 9 - 3 + 20
\][/tex]
4. Calculate [tex]\(-5 \times 9\)[/tex]:
[tex]\[
-5 \times 9 = -45
\][/tex]
5. Add the values together:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
6. Perform the arithmetic step-by-step:
[tex]\[
-45 - 3 = -48
\][/tex]
[tex]\[
-48 + 20 = -28
\][/tex]
Thus, [tex]\( f(3) = -28 \)[/tex].
1. Substitute [tex]\( x = 3 \)[/tex] into the function:
[tex]\[
f(3) = -5(3)^2 - (3) + 20
\][/tex]
2. Calculate [tex]\( 3^2 \)[/tex]:
[tex]\[
3^2 = 9
\][/tex]
3. Substitute and multiply:
[tex]\[
f(3) = -5 \times 9 - 3 + 20
\][/tex]
4. Calculate [tex]\(-5 \times 9\)[/tex]:
[tex]\[
-5 \times 9 = -45
\][/tex]
5. Add the values together:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
6. Perform the arithmetic step-by-step:
[tex]\[
-45 - 3 = -48
\][/tex]
[tex]\[
-48 + 20 = -28
\][/tex]
Thus, [tex]\( f(3) = -28 \)[/tex].
