M can have any value because M can represent any number because it is the unknown.
Answer:
The values for the given function f is defined by
is
a)
,
b)
and
c) 
Step-by-step explanation:
Given that the function f is defined by
Now to find the value of f(0), f(18) and f(-18)
Now take f(0)
Put x=0 in the given function
we get

Therefore 
Put x=18 in the given function
we get

Therefore 
Put x=-18 in the given function
we get

Therefore 
The values for the given function f is
a)
,
b)
and
c) 
I do believe that it still just $74.75.