Ответ:

1. 4 \(\cdot\) 5 \(\cdot\) \(\sqrt{17}\) \(\cdot\) \(\sqrt{2}\) \(\cdot\) \(\sqrt{2 \cdot 17}\) = 20 \(\cdot\) \(\sqrt{17}\) \(\cdot\) \(\sqrt{2}\) \(\cdot\) \(\sqrt{2}\) \(\cdot\) \(\sqrt{17}\).
2. 20 \(\cdot\) \(\sqrt{17} \cdot \sqrt{17}\) \(\cdot\) \(\sqrt{2} \cdot \sqrt{2}\) = 20 \(\cdot\) 17 \(\cdot\) 2.
3. \(\text{Ответ: }\) 680.