Question

For what value of k, (-4) is a zero of p(x)= x²-x-(2k-2)? *

a. 8
b. 11
c. 13
d. 15

Don't answer if you don't know the correct answer​

Answer 1

Answer:

In the given polynomial f(x)=x

2

−x−(2k+2), substitute x=−4 as shown below:

f(−4)=(−4)

2

−(−4)−(2k+2)=16+4−2k−2=18−2k

Therefore, f(−4)=18−2k.

Since it is given that x=−4 is a zero of the polynomial f(x)=x

2

−x−(2k+2), therefore f(−4)=0 that is:

18−2k=0

⇒2k=18

⇒k=

2

18

⇒k=9

Hence k=9.