given the function $f(x)=-5x^{2}-x + 20$, find $f(3)$. -28 -13 62 64

Explanation:

Step1: Substitute (x = 3) into the function

Given (f(x)=-5x^{2}-x + 20), when (x = 3), we have (f(3)=-5\times(3)^{2}-3 + 20).

Step2: Calculate the power

First, calculate ((3)^{2}=9). Then the expression becomes (f(3)=-5\times9-3 + 20).

Step3: Perform the multiplication

(-5\times9=-45), so (f(3)=-45-3 + 20).

Step4: Perform the addition and subtraction

(-45-3=-48), then (-48 + 20=-28).

Answer:

A. -28