1. **State the problem:** Solve the equation $2x + 5 = 9$ for $x$. 2. **Formula and rules:** To solve for $x$, we need to isolate $x$ on one side of the equation. We do this by performing inverse operations: subtraction and division. 3. **Step 1: Subtract 5 from both sides** to remove the constant term on the left: $$2x + 5 - 5 = 9 - 5$$ $$2x = 4$$ 4. **Step 2: Divide both sides by 2** to solve for $x$: $$\frac{\cancel{2}x}{\cancel{2}} = \frac{4}{2}$$ $$x = 2$$ 5. **Final answer:** $x = 2$. This means that when $x$ is 2, the original equation $2x + 5 = 9$ holds true.