13.5. \((\sqrt{32}-\sqrt{2})\cdot\sqrt{2}\)

\(\sqrt{32}=4\sqrt{2}\).

\((\sqrt{32}-\sqrt{2})\cdot\sqrt{2}=(4\sqrt{2}-\sqrt{2})\cdot\sqrt{2}=3\sqrt{2}\cdot\sqrt{2}=3\cdot2=6\).

Ответ: \(6\)