To express $9^{-2}$ using positive exponents, rewrite it as follows:

$9^{-2} = \frac{1}{9^2}$

This is the expression for $9^{-2}$ in terms of positive exponents.

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Would you like further clarification or details? Here are five related questions to expand your understanding:

1. How would you simplify $\frac{1}{9^2}$?
2. Can you rewrite $x^{-n}$ in general terms using positive exponents?
3. How do negative exponents work with fractions?
4. What is the significance of the base in exponentiation?
5. Can negative exponents apply to expressions with variables?

Tip: Negative exponents always represent the reciprocal of the base raised to the positive exponent.