The function is f (x) = 72+4x.

evaluate the function for f (9)

For solving a question like this where you have to find a function for a particular value, just put the given number in place of the unknown variable i. e. x in this case. Lets solve this function now.

We are to solve for f (9), so we will put 9 in place of x:

f (x) = 72+4x

f (9) = 72 + 4 (9)

f (9) = 72 + 36

f (9) = 108

so, your function for the value 9 is 108.