Answer
$\sqrt[7]{x^2} \text{ or }(\sqrt[7]{x})^2$
Work Step by Step
Recall the rational exponent property (pg. 382):
$a^{\frac{m}{n}}=\sqrt[n]{a^m}=(\sqrt[n]{a})^m$
Applying this property to the given expression ($m=2$, $n=7$, $a=x$), we get:
$x^{\frac{2}{7}}=\sqrt[7]{x^2} \text{ or }(\sqrt[7]{x})^2$
