For the given functions f and g, complete parts (a)-(h). For parts (a)-(d), also find the domain. f(x) =15x; g(x) =6x-5 (a) Find (f + 9)(x). (f + g)(x)= (Simplify your answer. Type an exact answer, using radicals as needed.) What is the domain of f+ g? Select the correct choice below and, if necessary, fill in the answer box to complete your choice O A. The domain is x (Use integers or fractions for any numbers in the expression. Use a comma to separate answers as needed.) O B. The domain is {x x is any real number). (b) Find (f - g)(x). (f- g)(x)= (Simplify your answer. Type an exact answer, using radicals as needed.)