1. Let's clarify what a negative exponent means. When you see an expression like $a^{-n}$ where $a \neq 0$ and $n > 0$, it means the reciprocal of $a^n$. 2. Specifically, $a^{-n} = \frac{1}{a^n}$. 3. For example, if we consider $2^{-3}$, it can be rewritten as $\frac{1}{2^3} = \frac{1}{8}$. 4. Hence, negative exponents are not impossible; they represent inverse powers. 5. If you have a specific expression to evaluate, apply this rule to correctly calculate the value.