15. For the following function, [4] a) Give the domain and range. b) Using the graph, find f(-1). -2 2 c) Using the graph, any values of x such that f(x) =-4 16. Given the function f defined by f(x) =x +7, evaluate each of the following functions. a) f(9) [1] b) f(3a) [2] c) f(b-1) [3] d) f(b-1)-f(b) [4]