Question

Show why x - 3 is a factor of m(x) = x³ x² - 5x - 3.

Answer 1

If m(x) = x^3 - x^2 - 5x - 3 then x - 3 is a factor.

Explanation:

By the Factor Theorem if (x - a) is a factor of f(x) then f(a) = 0.

m(x) = x^3 - x^2 - 5x - 3

m(3) = 27 - 9 - 15 - 3 = 0

- so x - 3 is a factor