Question

Which of the following is a factor of x^3-4x^2-18x+9

Answer 1

(x-2)(x^2-7x+3) most likely

Answer 2

Hello,

$x^3-4x^2-18x+9\\ =x^3+3x^2-7x^2-21x+3x+9\\ =x^2(x+3)-7x(x+3)+3(x+3)\\ =(x+3)(x^2-7x+3)\\ =(x+3)(x- \frac{7- \sqrt{37}}{2} )(x- \frac{7+ \sqrt{37}}{2} )$