Question

Rút gọn

\(\left(\sqrt{8}-3\sqrt{2}+\sqrt{10}\right)\sqrt{2}-\sqrt{5}\)

Answer 1

\(\left(\sqrt{8}-3\sqrt{2}+\sqrt{10}\right)\sqrt{2}-\sqrt{5}=\sqrt{8.2}-3\sqrt{2.2}+\sqrt{10.2}-\sqrt{5}=\sqrt{16}-3\sqrt{4}+\sqrt{20}-\sqrt{5}=4-3.2+\sqrt{4.5}-\sqrt{5}=-2+2\sqrt{5}-\sqrt{5}=\sqrt{5}-2\)

vậy \(\left(\sqrt{8}-3\sqrt{2}+\sqrt{10}\right)\sqrt{2}-\sqrt{5}=\sqrt{5}-2\)

Answer 2

=\(\sqrt{8.2}-3\sqrt{2.2}+\sqrt{10.2}-\sqrt{5}\)
= 4-6+\(2\sqrt{5}-\sqrt{5}\)
=\(\sqrt{5}\)-2