If f(x) and g(x) are given, explain how to find (f g)(x) and then how to find (g f)(x) . Choose the correct answer below. O A. To find (f g)(x) , the expression for f(x) should be substituted for x into g(x) . To find (gof f)(x) the expression for g(x) should be substituted for x into f(x) . O To find (f g)(x) , the expression for g(x) should be substituted for into f(x) . To find (g f)(x) the expression for f(x) should be substituted for x into g( x). To find (f g)(x) or (g f)(x) , multiply the expression for f(x) by the expression for g(x) .