Answer:
[tex]f( - 9) = 187[/tex]
Step-by-step explanation:
[tex]f(x) = {2x}^{2} - 5x - 20[/tex]
To find f(-9) , substitute the value of x that's -9 into f(x). That is for every x in f (x) replace it with - 9
We have
[tex]f( - 9) = 2 ({ - 9})^{2} - 5( - 9) - 20 \\ = 2(81) + 45 - 20 \\ = 162 + 25 \: \: \: \: \: \: \: \: \: \: \: \: \: \: [/tex]
We have the final answer as
[tex]f( - 9) = 187[/tex]
Hope this helps you
