1. **State the problem:** Factor the expression $x^9$. 2. **Recall the formula:** The expression $x^9$ is a power of $x$. It can be factored using the property of exponents or by recognizing it as a perfect power. 3. **Important rule:** $x^9 = (x^3)^3$ because $9 = 3 \times 3$. 4. **Factorization:** Using the difference of cubes formula, $a^3 - b^3 = (a - b)(a^2 + ab + b^2)$, but here we only have $x^9$ which is a perfect cube of $x^3$. 5. **Express $x^9$ as $(x^3)^3$:** $$x^9 = (x^3)^3$$ 6. **Further factorization:** If the problem is to factor $x^9 - 1$ or similar, we could use difference of cubes, but since it's just $x^9$, the factorization is simply $x^9 = x \cdot x \cdot x \cdot x \cdot x \cdot x \cdot x \cdot x \cdot x$ or $x^9$ itself. 7. **Conclusion:** The expression $x^9$ is already factored as a power of $x$. If you want to express it as a product of powers, it is $x^9$ or $(x^3)^3$. **Final answer:** $$x^9 = (x^3)^3$$