15.The graph is that of a fourth-degree polynomial function. Which of the following correctly shows three factors of the function? A) (x + 2)(x - 5)
B) (x - 3)(x + 5)
C) (x + 3)(x - 2)(x - 5)
D) (x - 3)(x + 2)(x + 5)

16.use synthetic division to perform (x4 - 3x + 5) ÷ (x-4).
option a. x3 + 4x^2 + 16x + 61 + 249 / x -4
option b. x3 + 4x^2 + 16x + 61 - 249 / x - 4
option c. x3 - 4x^2 + 16x + 61 + 249 / x - 4
option d. x3 - 4x^2 + 16x + 61 - 249 / x - 4

17. Find all real and non real roots of the function f (x) equals x^2 + 49.

option a. x equals -7, 7
option b. x equals -49i, 49i
option c. x = i + 7, i - 7
option d. x equals -7i, 7i​