1. **State the problem:** Solve the equation $3x - 9 = 27$ for $x$. 2. **Write the formula and rules:** To solve for $x$, isolate $x$ on one side of the equation by performing inverse operations. 3. **Add 9 to both sides:** $$3x - 9 + 9 = 27 + 9$$ $$3x = 36$$ 4. **Divide both sides by 3:** $$\frac{\cancel{3}x}{\cancel{3}} = \frac{36}{3}$$ $$x = 12$$ 5. **Final answer:** $$x = 12$$ This means the value of $x$ that satisfies the equation is 12.