Problem
Select the equivalent expression. \[ \sqrt[18]{\frac{b^{-1}}{b^{8}}} \] \( b^{2} \) \( b^{-2} \) Submit Answer \( b^{\frac{1}{2}} \) \( b^{-\frac{1}{2}} \)
Solution
Step 1 ：\(\sqrt[18]{\frac{b^{-1}}{b^{8}}} = \sqrt[18]{b^{-1-8}}\)
Step 2 ：\(\sqrt[18]{b^{-1-8}} = \sqrt[18]{b^{-9}}\)
Step 3 ：\(\sqrt[18]{b^{-9}} = b^{\frac{-9}{18}} = b^{-\frac{1}{2}}\)
