Question

If -4 is a root of the x2 +kx+4=0, then value of k is:

Answer 1

Answer:

5

Step-by-step explanation:

If - 4is the root of given polynomial then (x-4)is one of the factor of polynomial

When we divide it we will find that

K=5

Answer 2

Answer:

$\sqrt{x2 + kx + 4 } = - 4 \\ \sqrt{2x + kx + 4} = - 4 \\ 2x + kx + 4 = { - 4}^{2 } \\ 2x + kx + 4 = 16 \\ 2x + kx = 16 - 4 = 12 \\ kx = 12 - 2x \\ k = 12 - 2x \div \: x \\ k = 12 \div x - 2x \div x$