Problem
Select the equivalent expression. \[ \sqrt[18]{\frac{1}{y^{6} \cdot y^{3}}} \] \( y^{\frac{1}{2}} \) \( y^{-2} \) \( y^{-\frac{1}{2}} \) \( y^{2} \)
Solution
Step 1 ：\(\sqrt[18]{\frac{1}{y^{6} \cdot y^{3}}} \)
Step 2 ：\( = \sqrt[18]{y^{-9}} \)
Step 3 ：\( = y^{-\frac{1}{2}} \)
