Question

Giúp mình câu d với ạ

Answer 1

\(=\dfrac{1}{\sqrt{2}}\left(\sqrt{8-2\sqrt{7}}-\sqrt{8+2\sqrt{7}}\right)+\sqrt{7}\)

\(=\dfrac{1}{\sqrt{2}}\left(\sqrt{7}-1-\sqrt{7}-1\right)+\sqrt{7}\)

\(=-\sqrt{2}+\sqrt{7}\)