$\displaystyle \sqrt[7]{x^{23}}$
Are you saying that you want to know the derivative of $\displaystyle \displaystyle \begin{align*} y = \sqrt[7]{x^{23}} \end{align*}$? If so, note that $\displaystyle \displaystyle \begin{align*} \sqrt[7]{x^{23}} = \left(x^{23}\right)^{\frac{1}{7}} = x^{\frac{23}{7}} \end{align*}$. The derivative should be easy to find now.