To generate an expression equivalent to \(\frac{5^{-9}}{4^{-12}}\) using positive exponents only, we can apply the property of negative exponents. The property states that \(a^{-n} = \frac{1}{a^n}\). Therefore, we can rewrite the negative exponents as follows:
\[ \frac{5^{-9}}{4^{-12}} = \frac{1}{5^{9}} \div \frac{1}{4^{12}} \]
Dividing by a fraction is the same as multiplying by its reciprocal:
\[ = \frac{1}{5^{9}} \times 4^{12} = \frac{4^{12}}{5^{9}} \]
Thus, the expression equivalent to \(\frac{5^{-9}}{4^{-12}}\) with positive exponents only is:
\[ \frac{4^{12}}{5^{9}} \]