To simplify the expression \( 5^9 \cdot 5^{-13} \) using the properties of integer exponents, we can apply the property which states that \( a^m \cdot a^n = a^{m+n} \).
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Combine the exponents: \[ 5^9 \cdot 5^{-13} = 5^{9 + (-13)} = 5^{9 - 13} = 5^{-4} \]
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Rewrite \( 5^{-4} \) with a positive exponent: \[ 5^{-4} = \frac{1}{5^4} \]
Thus, the equivalent expression to \( 5^9 \cdot 5^{-13} \) with only positive exponents is: \[ \frac{1}{5^4} \]