To find an equivalent expression to \( 81^{-12} \), let's first rewrite it in a more manageable form.
The expression \( 81^{-12} \) can be expressed as:
\[ \frac{1}{81^{12}} \]
Next, we also know that \( 81 \) can be written as \( 3^4 \). Therefore, we can rewrite \( 81^{12} \) as follows:
\[ 81^{12} = (3^4)^{12} = 3^{4 \cdot 12} = 3^{48} \]
Thus, we can express \( 81^{-12} \) as:
\[ 81^{-12} = \frac{1}{81^{12}} = \frac{1}{3^{48}} \]
Now let’s analyze the options provided:
- \( -\sqrt{81} \): This evaluates to \(-9\), not equivalent.
- \( \sqrt{81} \): This evaluates to \(9\), not equivalent.
- \( \frac{1}{\sqrt{81}} \): This evaluates to \(\frac{1}{9}\), not equivalent.
- \( -\frac{1}{\sqrt{81}} \): This evaluates to \(-\frac{1}{9}\), not equivalent.
None of the options given appears to be a direct equivalent expression to \( 81^{-12} \) or \(\frac{1}{81^{12}}\).
If any of the options may have typographical errors, please re-check or clarify, but based on the given expressions, none is equivalent to \( 81^{-12} \).