To rewrite \( 15^{-38} \) with positive exponents only, you can use the property of negative integer exponents, which states that \( a^{-n} = \frac{1}{a^n} \).
Applying this property:
\[ 15^{-38} = \frac{1}{15^{38}} \]
So, \( 15^{-38} \) can be rewritten as:
\[ \frac{1}{15^{38}} \]
This expression has positive exponents only.