Question

\(2\sqrt{20}+\sqrt{50}+3\sqrt{80}-\sqrt{320}\)

Answer 1

\(2\sqrt{20}+\sqrt{50}+3\sqrt{80}-\sqrt{320}\)

\(=2\sqrt{4.5}+\sqrt{2.25}+3\sqrt{16.5}-\sqrt{64.5}\)

\(=2.2\sqrt{5}+5\sqrt{2}+3.4\sqrt{5}-8\sqrt{5}\)

\(=\left(4+12-8\right)\sqrt{5}+5\sqrt{2}\)

\(=8\sqrt{5}+5\sqrt{2}\)

P/s: Em mới lớp 5 nên làm đại, sai thì thông cảm ạ.

Answer 2

\(2\sqrt{20}+\sqrt{50}+3\sqrt{80}-\sqrt{320}\)

\(=2\sqrt{4.5}+\sqrt{25.2}+3\sqrt{16.5}-\sqrt{64.5}\)

\(=2.2\sqrt{5}+3.4\sqrt{5}-8\sqrt{5}+5\sqrt{2}\)

\(=4\sqrt{5}+12\sqrt{5}-8\sqrt{5}+5\sqrt{2}\)

\(=8\sqrt{5}+5\sqrt{2}\)