Câu hỏi của ➻❥tử↭tђầภ➻❥ ♍

\(a.\sqrt{2}+\sqrt{32}+\sqrt{72}-\sqrt{18}\) \(=\sqrt{2}+\sqrt{16.2}+\sqrt{36.2}-\sqrt{9.2}\) \(=\sqrt{2}+4\sqrt{2}+6\sqrt{2}-3\sqrt{2}\)\(=8\sqrt{2}\) \(c.5-\sqrt{\left(2-\sqrt{5}\right)^2}\)\(=5-\left|2-\sqrt{5}\right|\)\(=5-\left(2-\sqrt{5}\right)=5-2+\sqrt{5}=3+\sqrt{5}\) Câu trả lời: \(a.\sqrt{2}+\sqrt{32}+\sqrt{72}-\sqrt{18}\) \(=\sqrt{2}+\sqrt{16.2}+\sqrt{36.2}-\sqrt{9.2}\) \(=\sqrt{2}+4\sqrt{2}+6\sqrt{2}-3\sqrt{2}\)\(=8\sqrt{2}\) \(c.5-\sqrt{\left(2-\sqrt{5}\right)^2}\)\(=5-\left|2-\sqrt{5}\right|\)\(=5-\left(2-\sqrt{5}\right)=5-2+\sqrt{5}=3+\sqrt{5}\)