Answer
$\frac{p^{8}\sqrt p}{11}$
Work Step by Step
$\sqrt(\frac{p^{17}}{121})=\sqrt(p^{16}\times p)\times\sqrt(\frac{1}{121})=\sqrt(p^{16})\times \sqrt p\times\sqrt(\frac{1}{121})=\frac{p^{8}\sqrt p}{11}$
We know that $\sqrt (p^{16})=p^{8}$, because $(p^{8})^{2}=p^{8\times2}=p^{16}$
We know that $\sqrt(\frac{1}{121})=\frac{1}{11}$, because $(\frac{1}{11})^{2}=\frac{1}{121}$