Question

Is x + 3 a factor of the polynomial 2x^3 + 5x - 3?

Answer 1

Answer: n = - 6

Step-by-step explanation:

Given (x + h) is a factor of a polynomial f(x) then f(- h) = 0

Here

f(x) = x³ + 2x² - 5x + n and (x + 3) is a factor then f(- 3) = 0 , that is

f(- 3) = (- 3)³ + 2(- 3)² - 5(- 3) + n = 0 , so

- 27 + 2(9) + 15 + n = 0

- 27 + 18 + 15 + n = 0

6 + n = 0 ( subtract 6 from both sides )

n = - 6