To convert the expression \( \sqrt[3]{216} \) into a form with a rational exponent, we can rewrite it using the properties of exponents.
The general form for taking a root and using rational exponents is:
\[ \sqrt[n]{a} = a^{\frac{1}{n}} \]
In this case, we have \( \sqrt[3]{216} \), which can be expressed as:
\[ 216^{\frac{1}{3}} \]
Therefore, \( \sqrt[3]{216} = 216^{\frac{1}{3}} \).
The expression you provided, \( 216^{-\frac{1}{3}} \), indicates that you are looking for a negative exponent.
If we write
\[ \sqrt[3]{216} \neq 216^{-\frac{1}{3}} \]
But if you mean to find the equivalent expression involving a negative exponent:
Since \( 216^{-1/3} \) would represent the reciprocal (i.e., \( \frac{1}{\sqrt[3]{216}} \)), the equivalent expression you are looking for that would imply \( \sqrt[3]{216} \) being taken in inverse would give us the negative exponent as:
The answer to your question would therefore be −1/3 if considering the inversion.
If you are just representing \(216^{\frac{1}{3}}\), then it is \(\frac{1}{3}\).
If your question means specifically \( \sqrt[3]{216} \), the rational exponent is:
\( \frac{1}{3} \).