Answer :
To find [tex]\( f(3) \)[/tex] for the function [tex]\( f(x) = -5x^2 - x + 20 \)[/tex], we need to substitute [tex]\( x = 3 \)[/tex] into the function and perform the calculations step by step.
1. Start with the function:
[tex]\[
f(x) = -5x^2 - x + 20
\][/tex]
2. Substitute [tex]\( x = 3 \)[/tex] into the function:
[tex]\[
f(3) = -5(3)^2 - (3) + 20
\][/tex]
3. Calculate the square of 3:
[tex]\[
3^2 = 9
\][/tex]
4. Multiply this result by -5:
[tex]\[
-5 \times 9 = -45
\][/tex]
5. Now substitute these values back into the function expression:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
6. Calculate the expression from left to right:
[tex]\[
-45 - 3 = -48
\][/tex]
7. Finally, add 20 to the result:
[tex]\[
-48 + 20 = -28
\][/tex]
Therefore, [tex]\( f(3) = -28 \)[/tex].
1. Start with the function:
[tex]\[
f(x) = -5x^2 - x + 20
\][/tex]
2. Substitute [tex]\( x = 3 \)[/tex] into the function:
[tex]\[
f(3) = -5(3)^2 - (3) + 20
\][/tex]
3. Calculate the square of 3:
[tex]\[
3^2 = 9
\][/tex]
4. Multiply this result by -5:
[tex]\[
-5 \times 9 = -45
\][/tex]
5. Now substitute these values back into the function expression:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
6. Calculate the expression from left to right:
[tex]\[
-45 - 3 = -48
\][/tex]
7. Finally, add 20 to the result:
[tex]\[
-48 + 20 = -28
\][/tex]
Therefore, [tex]\( f(3) = -28 \)[/tex].
