Question

Which of the following is the value of k
If one root of the quadratic equation x²+
Kx-8=0 is - 4​

Answer 1

Answer:

SEE THE ATTACHMENT.......

Answer 2

Given,

A quadratic equation x²+Kx-8=0 where one root is -4.

To find,

The value of k.

Solution,

If -4 is a root of the equation  x²+Kx-8=0 then if we put -4 in the pace of x we would get the final answer as 0 or in other words, -4 would satisfy the equation x²+Kx-8=0.

Hence,

⇒   x²+Kx-8=0.

⇒   (-4)²+ K(-4) - 8 = 0

⇒   16 -4k - 8 = 0

⇒   8 - 4k = 0.

-4k which is on the Left-Hand Side of the equation would be shifted to the Right-Hand Side of the equation and its sign would change from -4k to +4k.

⇒   8 = 4k.

⇒  k = 2.

Hence,  the value of k If one root of the quadratic equation x²+

Kx-8=0 is - 4​ should be 2.