1. The problem asks if the number 12 is a solution to the equation $k - 9 = 3$. 2. To check, substitute $k = 12$ into the equation. 3. Substitute: $$12 - 9 = 3$$ 4. Simplify the left side: $$3 = 3$$ 5. Since both sides are equal, the equation holds true when $k = 12$. 6. Therefore, 12 is a solution to the equation $k - 9 = 3$.