Answer:
x^21/5
Explanation:
To change this expression to an expression with a rational exponent, we need to change the radical to a rational (fractional) exponent. Just as square root is a one half power and cuberoot is a one-third power, a fifth root is a one-fifth power.
Once the radical is changed to a fraction, we will just use the exponent rule that says when you raise a power to a power, you multiply exponents.
see image.