Answer:
we can see that this function is written in terms of x
H(x) = 18 - x
in order to evaluate it for x = - 6, we will change the x to -6 in the bracket next to H and replace any x in the function with that value
So,
H(-6) = 18 - (-6)
H(-6) = 18 + 6
H(-6) = 24