Answer:
[tex] {( {x}^{ \frac{1}{4} } {y}^{16} )}^{ \frac{1}{2} } = {( {x}^{ \frac{1}{4}. \frac{1}{2} } {y}^{ \frac{16}{2} } )} \\ = {x}^{ \frac{1}{8} } {y}^{8} [/tex]