Question

\(\sqrt{8+2\sqrt{15}}\) rút gọn

Answer 1

\(\sqrt{8+2\sqrt{15}}\)

\(=\sqrt{3+2\sqrt{15}+5}\)

\(=\sqrt{\left(\sqrt{3}\right)^2+2\cdot\sqrt{3}\cdot\sqrt{5}+\left(\sqrt{5}\right)^2}\)

\(=\sqrt{\left(\sqrt{3}+\sqrt{5}\right)^2}\)

\(=\left|\sqrt{3}+\sqrt{5}\right|\)

\(=\sqrt{3}+\sqrt{5}\)

Answer 2

\(=\sqrt{5+2\cdot\sqrt{5}\cdot\sqrt{3}+3}\)

=căn (căn 5+căn 3)^2

=căn 5+căn 3