1. Problem: Solve the equation $-9x - 5 = 13$. 2. Formula and rules: To solve linear equations, isolate the variable $x$ by performing inverse operations. 3. Step 1: Add 5 to both sides: $$-9x - 5 + 5 = 13 + 5$$ $$-9x = 18$$ 4. Step 2: Divide both sides by $-9$: $$x = \frac{18}{-9} = -2$$ 5. Final answer: $x = -2$. This means when $x$ is $-2$, the equation holds true.