Question

question
given $f(x)=-x^{2}+5x - 18$, find $f(-3)$

Explanation:

Step1: Substitute x = -3

$f(-3)=-(-3)^2 + 5\times(-3)-18$

Step2: Calculate powers

$f(-3)=-(9)+5\times(-3)-18$

Step3: Calculate multiplications

$f(-3)=-9 - 15-18$

Step4: Calculate subtractions

$f(-3)=-9-15 - 18=-42$

Answer:

$-42$