Question

6. If x2 - x - 42 = (x +k) (x + 6) then the value of k is
(A) 6
(B) -6
(C) 7
(D) -7

Answer 1

Answer:

x2 – x – 42 = (x + k) (x + 6) ⇒ x2 – 7x + 6x – 42 = (x + k) (x + 6) ⇒x (x – 7) + 6 (x – 7) = (x + k) (x + 6) ⇒ (x – 7) (x + 6) = (x + k) (x + 6) On comparison k = – 7Read more on Sarthaks.com - https://www.sarthaks.com/820643/if-x-2-x-42-x-k-x-6-then-find-the-value-of-k?show=820651#a820651