Question

for what value of k , -4 is a zero of the polynomial x square -x - (2k + 2) ????

Answer 1

-4 is the zero of the given polynomial, this means if we put x as -4 then resultant will be 0.
4^2 - 2(k-1) = 0
k-1=-16/-2
k = 8
k = 8+1 = 9
Regards

Answer 2

x=-4
x^2-x-(2k+2)=0
putting x value
(-4)^2-(-4)-(2k+2)=0
16+4=(2k+2)
20-2=2k
18/2=k
k=9