18. Suppose f(x) = - and g(x) = vx+10 . Which of these expressions is equivalent to f (g(-1))? X a. b. c. -3 d. 3 19. If f(x) = log 4x and g(x) = x- - 2, which of these expressions is equivalent to f (g(4))? a. log 4 + log 14 b. log- 16 - 2 C. log- 14 d. log 4 x log 14 20. If f(x) = and g(x) = 1 log x 8+ x -, what is the domain of y = f(x)g(x)? a. (x ER x # -8 and x # 1} C. (x ER x > 0 and x # 1} b. (x ER | x > 0} d. (x ER | x > 0 and x # 8}