Question

Use the functions f(x) = 4x − 5 and g(x) = 3x + 9 to complete the function operations listed below.

Answer 1

A.  (f + g)(x) = f(x) + g(x) = 4x - 5 + 3x + 9 = 7x + 4

B. f.g (x)   = f(x) * g(x) = (4x - 5)*(3x + 9) = 12x^2 + 36x -  15x - 45
                =  12x^2 + 21x - 45

C  Replace the x in f(x) by g(x):-
  =  4(3x + 9) - 5
  = 12x + 36 - 5
  = 12x  + 31