Step-by-step explanation:
f(x) = x² - 5x - 9
To solve both expressions first find f( -4) and f(5)
For f(- 4)
Substitute the value of x that's - 4 into the expression
That's
f(-4) = (-4)² - 5(-4) - 9
= 16 + 20 - 9
= 36 - 9
f(-4) = 27
For f(-5)
Substitute 5 into f (x)
That's
f(5) = 5² - 5(5) - 9
= 25 - 25 - 9
f(5) = - 9
A).
f(-4) + f(5) = 27 - 9 = 18
B).
f(-4) - f(5) = 27 -- 9 = 27 + 9 = 36
Hope this helps you
