\(\sqrt{7 \cdot 5^2} = \sqrt{7} \cdot \sqrt{5^2} = \sqrt{7} \cdot 5 = 5\sqrt{7}\) \(\sqrt{7 \cdot 3^4} = \sqrt{7} \cdot \sqrt{3^4} = \sqrt{7} \cdot 3^{4/2} = \sqrt{7} \cdot 3^2 = \sqrt{7} \cdot 9 = 9\sqrt{7}\) \((5\sqrt{7}) \cdot (9\sqrt{7}) = 5 \cdot 9 \cdot \sqrt{7} \cdot \sqrt{7}\)\(45 \cdot 7 = 315\)
Ответ: 315