Question

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

Answer 1

According to the question:

since, 4 is a zero of given polynomial so when 4 is taken in place of x in the polynomial then the polynomial will become equal to zero.

the given polynomial is

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

putting 4 in place of x and equalising it with zero

${(4)}^{2} - (4) - (2k + 2) = 0 \\ \\ 16 - 4 - 2k - 2 = 0 \\ \\ 16 - 6 - 2k = 0 \\ \\ 10 - 2k = 0 \\ \\ 10 = 2k \\ \\ k = \frac{10}{2} = 5$

So the value of k will be 5.