To convert the expression \( 5 - \sqrt[3]{x} \) to an equivalent expression using rational exponents, we first need to rewrite the cube root as a rational exponent.
The expression \( \sqrt[3]{x} \) can be written in terms of rational exponents as:
\[ \sqrt[3]{x} = x^{\frac{1}{3}} \]
Therefore, the expression \( 5 - \sqrt[3]{x} \) can be rewritten as:
\[ 5 - x^{\frac{1}{3}} \]
The rational exponent in this expression is \( \frac{1}{3} \).
So, the final answer is:
\[ \frac{1}{3} \]