If x – 4 is a factor of x

^{2}– x – k, then k is-
**A.**

4 -
**B.**

12 -
**C.**

20 -
**D.**

2

##### Correct Answer: Option B

##### Explanation

Let f(x) = x^{2} – x – k

Then by the factor theorem,

(x – 4): f(4) = (4)^{2} – (4) – k = 0

16 – 4 – k = 0

12 – k = 0

k = 12

There is an explanation video available below.