#### Answer

$7y^{2}\sqrt {y}$

#### Work Step by Step

$\frac{\sqrt {98y^{6}}}{\sqrt {2y}}$
=$\sqrt \frac{98y^{6}}{ {2y}}$
=$\sqrt \frac{98}{2}\times\sqrt \frac{y^{6}}{y}$
=$\sqrt {49}\times\sqrt {y^{6-1}}$
=$7\times\sqrt {y^{5}}$
=$7\times\sqrt {y^{4}}\times\sqrt {y^{1}}$
=$7y^{2}\sqrt {y}$