Answer :
To find [tex]\( f(3) \)[/tex] for the function [tex]\( f(x) = -5x^2 - x + 20 \)[/tex]:
1. First, plug in [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 [tex]\( 9 \)[/tex] back into the equation:
[tex]\[
f(3) = -5(9) - 3 + 20
\][/tex]
4. Multiply [tex]\( -5 \)[/tex] by [tex]\( 9 \)[/tex]:
[tex]\[
-5 \times 9 = -45
\][/tex]
5. Substitute [tex]\( -45 \)[/tex] back into the equation:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
6. Add and subtract in the order from left to right:
- First, add [tex]\( -45 \)[/tex] and [tex]\( -3 \)[/tex]:
[tex]\[
-45 - 3 = -48
\][/tex]
- Then, add [tex]\( -48 \)[/tex] and [tex]\( 20 \)[/tex]:
[tex]\[
-48 + 20 = -28
\][/tex]
Therefore, [tex]\( f(3) = -28 \)[/tex].
1. First, plug in [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 [tex]\( 9 \)[/tex] back into the equation:
[tex]\[
f(3) = -5(9) - 3 + 20
\][/tex]
4. Multiply [tex]\( -5 \)[/tex] by [tex]\( 9 \)[/tex]:
[tex]\[
-5 \times 9 = -45
\][/tex]
5. Substitute [tex]\( -45 \)[/tex] back into the equation:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
6. Add and subtract in the order from left to right:
- First, add [tex]\( -45 \)[/tex] and [tex]\( -3 \)[/tex]:
[tex]\[
-45 - 3 = -48
\][/tex]
- Then, add [tex]\( -48 \)[/tex] and [tex]\( 20 \)[/tex]:
[tex]\[
-48 + 20 = -28
\][/tex]
Therefore, [tex]\( f(3) = -28 \)[/tex].
