When doing f(x) functions, what ever number is in the parenthesis, substitute that for the corresponding letter. Note: there can be any letter in from of the (x), just pay attention to the letter in the parenthesis. Her is how yo do this one:
h(x)= x-9
f(8)
h(x)=8-9
h(x)= -1
hope this helps! Comment if you have any questions.
