Chapter 1.8, Problem 6P

Tell whether each equation is true, false, or open. Explain

$7k-8k=-15$

To determine

To find: Whether the equation $7k-8k=-15$ is true, false or open.

Answer to Problem 6P

The equation $7k-8k=-15$ is open as the value of $n$ is not given.

Explanation of Solution

Given:

The equation is $7k-8k=-15$ .

Calculation:

Simplify the equation $7k-8k=-15$ as follows:

  $\begin{array}{c}7k-8k=-15\\ -k=-15\end{array}$

From the above equation, it is not possible to tell whether LHS is equal to RHS until the value of n is given. Therefore, it is an open equation.

Thus, the equation $7k-8k=-15$ is open as the value of $n$ is not given.