To simplify the expression \( 13^{-5} \cdot 13^{-11} \), we can use the property of exponents that states \( a^m \cdot a^n = a^{m+n} \).
Applying this property:
\[ 13^{-5} \cdot 13^{-11} = 13^{-5 + (-11)} = 13^{-16} \]
Now, to convert \( 13^{-16} \) to an expression with only positive exponents, we use the property that \( a^{-n} = \frac{1}{a^n} \):
\[ 13^{-16} = \frac{1}{13^{16}} \]
Now, let's compare this result to the provided options.
None of the options you provided directly match \( \frac{1}{13^{16}} \), but we can simplify the choices. The first options with \( \frac{1}{13^{16}} \) would be the correct choice.
So the equivalent expression with only positive exponents is:
Start Fraction 1 over 13 superscript 16 baseline end fraction.