Question

chứng minh rằng : \(\sqrt{7-2\sqrt{10}}+\sqrt{2}=\sqrt{5}\)

Answer 1

\(\sqrt{7-2\sqrt{10}}+\sqrt{2}=\sqrt{5-2\sqrt{2}.\sqrt{5}+2}+\sqrt{2}=\sqrt{\left(\sqrt{5}-\sqrt{2}\right)^2}+\sqrt{2}=\sqrt{5}-\sqrt{2}+\sqrt{2}=\sqrt{5}\)

Answer 2