Problem
Select the equivalent expression. \[ \sqrt[9]{\frac{y}{y^{4}}} \]
Solution
Step 1 ：\( \sqrt[9]{\frac{y}{y^{4}}} = \sqrt[9]{y^{1-4}} \)
Step 2 ：\( \sqrt[9]{y^{1-4}} = \sqrt[9]{y^{-3}} \)
Step 3 ：\( \sqrt[9]{y^{-3}} = y^{\frac{-3}{9}} \)
