Ответ:
- \(2\sqrt{2}+\sqrt{50}-\sqrt{98}=2\sqrt{2}+5\sqrt{2}-7\sqrt{2}=0\).
- \((3\sqrt{5}-\sqrt{20})\sqrt{5}=(3\sqrt{5}-2\sqrt{5})\sqrt{5}=\sqrt{5}\cdot\sqrt{5}=5\).
- \((\sqrt{3}+\sqrt{2})^2=3+2\sqrt{6}+2=5+2\sqrt{6}\).
Ответ: а) 0; б) 5; в) \(5+2\sqrt{6}\).
