Question

If x – 3 is a factor of x2 – kx + 12, then find the value of k. Also, find the other factor of the polynomial for this value of k.

Answer 1

$= {x}^{2} - kx + 12$

$x - 3 = 0$

$x = 3$

$= {(3)}^{2} - k(3) + 12$

$= 9 - 3k + 12$

$= - 3k + 3 = 0$

$- 3k = - 3$

$k = \frac{ - 3}{ - 3}$

$k = 1$