To apply the property of negative integer exponents, we can use the rule that states:
\[ a^{-m} = \frac{1}{a^m} \]
We also have the property of exponents that states when multiplying like bases, we can add their exponents:
\[ a^m \cdot a^n = a^{m+n} \]
Using these properties, let's simplify the expression:
- Combine the exponents:
\[ 7^{-3} \cdot 7^{-5} = 7^{-3 + (-5)} = 7^{-8} \]
- Now apply the property of negative exponents:
\[ 7^{-8} = \frac{1}{7^8} \]
Thus, the expression \( 7^{-3} \cdot 7^{-5} \) can be rewritten as:
\[ \frac{1}{7^8} \]
This is the equivalent expression with positive exponents only.