1. **Problem:** Rewrite the expression $x^{-3}$ with positive exponents only. 2. **Formula and rule:** Negative exponents mean the reciprocal of the base raised to the positive exponent: $$a^{-n} = \frac{1}{a^n}$$ 3. **Work:** $$x^{-3} = \frac{1}{x^3}$$ 4. **Explanation:** When you see a negative exponent, you move the base to the denominator and make the exponent positive. **Final answer:** $\frac{1}{x^3}$