17) $$\frac{\sqrt{16a^9} \cdot \sqrt{4b^3}}{\sqrt{a^5b^3}} = \frac{\sqrt{16} \cdot \sqrt{a^9} \cdot \sqrt{4} \cdot \sqrt{b^3}}{\sqrt{a^5} \cdot \sqrt{b^3}} = \frac{4 \cdot a^{9/2} \cdot 2 \cdot b^{3/2}}{a^{5/2} \cdot b^{3/2}} = 8 \cdot a^{(9/2 - 5/2)} = 8 \cdot a^{4/2} = 8a^2$$
Подставим значения a = 9 и b = 11:
$$8 \cdot 9^2 = 8 \cdot 81 = 648$$
Ответ: 648