Question

For what value of k, -4 is a zero of the polynomial x² - x - (2k + 2).​

Answer 1

QUESTION :-

For what value of k, -4 is a zero of the polynomial x² - x - (2k + 2).

SOLUTION :-

Given polynomial = f(x)

= x² - x - (2k + 2)

-4 is a zero of f(x), so x = -4

f(-4) = (-4)² - (-4) - (2k + 2) = 0

➡ 16 + 4 - 2k - 2 = 0

➡ 18 - 2k = 0

2k = 18 ➡ k = 18/2 = 9

.°. The value of 'k' is 9

Answer 2

Given,

${x }^{2} - x - (2k + 2)$

Here,

X= -4

$f( - 4) = ( - {4}^{2} ) - ( - 4) - (2k + 2) = 0$

16+4-2k-2=0

18-2k=0

$k = \frac{18}{2}$

k=9