Answer:
[tex]x {y}^{3} \sqrt{25 {x}^{7} {y}^{4} } \\ \\ = {xy}^{3} \sqrt{ {5}^{2} {x}^{7} {y}^{4} } \\ \\ = {xy}^{3} \times \{ ({5}^{2} ) {}^{ \frac{1}{2} } ( {x}^{7} ) {}^{ \frac{1}{2} } ( {y}^{4} ) {}^{ \frac{1}{2} } \} \\ \\ = {xy}^{3} \times (5 \times {x}^{ \frac{7}{2} } \times {y}^{2} ) \\ \\ = 5 \times {x}^{(1 + \frac{7}{2}) } \times {y}^{(3 + 2)} \\ \\ = { \boxed{ \boxed{5 {y}^{5} \sqrt{ {x}^{9} } }}}[/tex]
