1. **State the problem:** Solve the equation $q - 12 = 3q + 6$ for $q$. 2. **Write down the equation:** $$q - 12 = 3q + 6$$ 3. **Goal:** Isolate $q$ on one side of the equation. 4. **Step 1: Move all terms involving $q$ to one side.** Subtract $q$ from both sides: $$q - 12 - q = 3q + 6 - q$$ Simplifies to: $$-12 = 2q + 6$$ 5. **Step 2: Move constants to the other side.** Subtract 6 from both sides: $$-12 - 6 = 2q + 6 - 6$$ Simplifies to: $$-18 = 2q$$ 6. **Step 3: Solve for $q$.** Divide both sides by 2: $$q = \frac{-18}{2}$$ Simplifies to: $$q = -9$$ 7. **Final answer:** $$\boxed{q = -9}$$ **Explanation:** We rearranged the equation to isolate $q$ by moving all $q$ terms to one side and constants to the other, then divided to solve for $q$.