1. **State the problem:** Solve the inequality $X + 9 \geq 12$. 2. **Formula and rules:** To solve inequalities, we isolate the variable on one side by performing inverse operations. Adding or subtracting the same number on both sides keeps the inequality direction the same. 3. **Isolate $X$:** Subtract 9 from both sides: $$X + 9 - \cancel{9} \geq 12 - \cancel{9}$$ which simplifies to $$X \geq 3$$ 4. **Interpretation:** The solution means $X$ can be any number greater than or equal to 3. 5. **Final answer:** $$\boxed{X \geq 3}$$