1. The problem is to find the value of the expression or equation that your textbook shows as -6. 2. Since you did not provide the exact expression, I will explain a common scenario where the answer is -6, such as solving a linear equation. 3. For example, consider the equation $2x + 4 = -8$. 4. To solve for $x$, subtract 4 from both sides: $$2x + 4 - 4 = -8 - 4$$ which simplifies to $$2x = -12$$. 5. Next, divide both sides by 2: $$x = \frac{-12}{2} = -6$$. 6. This shows how the solution $x = -6$ can be obtained. 7. If you provide the exact problem, I can give a more precise explanation.