Chapter 4, Problem 12STP

To determine

To find: The value of $k$ .

Answer to Problem 12STP

The value of $k$ is $-1$ .

Explanation of Solution

Given:

The given equation is:

  $x^2+kx-12=0\dots \left(1\right)$

The one root of the above equation is $4$ .

As root satisfies the equation,

So the value of $k$ is calculated as:

  $\begin{array}{c}{\left(4\right)}^2+k\left(4\right)-12=0\\ 16+4k-12=0\\ 4k=-4\\ k=-1\end{array}$

Therefore the value of $k$ is $-1$ .