Question

Find the value of k for which (-4)is a zero of the polynomial x square minus x-(2k+2)​

Answer 1

Answer:

K = 9.

Step-by-step explanation:

x²-x-(2k+2)

x²-x -2k+2=0

(-4)² -(-4) -2k-2=0

16 +4 -2-2k=0

20-2 -2k=0

18 -2k =0

-2k = 0-18

-2k = -18

K = - 18/ -2

K = 9

Answer 2

${ \huge{ \underline{ \underline{ \sf{ \green{GivEn : }}}}}}$

• -4 is a zero of polynomial x² - x -(2k + 2)

${ \huge{ \underline{ \underline{ \sf{ \green{To \: find :}}}}}}$

• What's the value of k?

${ \huge{ \underline{ \underline{ \sf{ \green{SoluTion : }}}}}}$

Given that,

-4 is a zero of polynomial x² - x -(2k + 2)

Hence, x = -4

Putting x = -4 :-

⟶ x² - x -2k - 2 = 0

⟶ (-4)² -(-4) - 2k - 2 = 0

⟶ 16 + 4 - 2k - 2 = 0

⟶ 20 - 2 - 2k = 0

⟶ 18 - 2k = 0

⟶ 2k = 18

⟶ k = 9

Therefore, value of k is = 9

___________________________________________________

Verification :-

⟶ x² - x -(2×9+2) = 0

⟶ x² - x - (18 + 2) = 0

⟶ x² - x - 20 = 0

⟶ x² - x - 20 =0

⟶ x² + 4x - 5x - 20 =0

⟶ x(x + 4) - 5(x + 4) =0

⟶ (x - 5)(x + 4) =0

Hence, x = 5 or x = -4

(Verified)