Answer
(a) $\frac{\sqrt[3]{x^{2}}}{x}$
(b) $\frac{\sqrt[6]{x}}{x}$
(c) $\frac{\sqrt[7]{x^{4}}}{x}$
Work Step by Step
(a) $\displaystyle \frac{1}{\sqrt[3]{x}}=\frac{1}{\sqrt[3]{x}} \displaystyle \frac{\sqrt[3]{x^{2}}}{\sqrt[3]{x^{2}}}=\frac{\sqrt[3]{x^{2}}}{x}$
(b) $\displaystyle \frac{1}{\sqrt[6]{x^{5}}}=\frac{1}{\sqrt[6]{x^{5}}} \displaystyle \frac{\sqrt[6]{x}}{\sqrt[6]{x}}=\frac{\sqrt[6]{x}}{x}$
(c) $\displaystyle \frac{1}{\sqrt[7]{x^{3}}}=\frac{1}{\sqrt[7]{x^{3}}} \displaystyle \frac{\sqrt[7]{x^{4}}}{\sqrt[7]{x^{4}}}=\frac{\sqrt[7]{x^4}}{\sqrt[7]{x^7}}=\frac{\sqrt[7]{x^{4}}}{x}$