Question

Tính 1 phần 3 căn 18 + 2 căn 45 - căn 72 + 3 căn 20

Answer 1

\(\dfrac{1}{3}\sqrt{18}+2\sqrt{45}-\sqrt{72}+3\sqrt{20}\)

\(=\dfrac{1}{3}\sqrt{9\times2}+2\sqrt{9\times5}-\sqrt{9\times8}+3\sqrt{4\times5}\)

\(=\sqrt{2}+6\sqrt{5}-6\sqrt{2}+6\sqrt{5}\) \(=12\sqrt{5}-5\sqrt{2}\)

Answer 2

Answer 3

\(\dfrac{1}{3}\sqrt{18}+2\sqrt{45}-\sqrt{72}+3\sqrt{20}\)

\(=\sqrt{2}+6\sqrt{5}-6\sqrt{2}+6\sqrt{5}\)

\(=12\sqrt{5}-5\sqrt{2}\)