в) $$\frac{\sqrt{216}}{\sqrt{6}} = \sqrt{\frac{216}{6}} = \sqrt{36} = 6$$
г) $$\sqrt{5^4 \cdot 3^2} = \sqrt{(5^2)^2 \cdot 3^2} = 5^2 \cdot 3 = 25 \cdot 3 = 75$$
Ответ: в) $$6$$; г) $$75$$