Решение:
\[ \sqrt{50} = \sqrt{25 \times 2} = 5\sqrt{2} \]
\[ (3\sqrt{2} + 5\sqrt{2}) \times \sqrt{2} = (8\sqrt{2}) \times \sqrt{2} \]
\[ 8\sqrt{2} \times \sqrt{2} = 8 \times (\sqrt{2} \times \sqrt{2}) = 8 \times 2 = 16 \]
Ответ: 16