Question

[Hiền Lê]

Rút gọn biểu thức

\(\sqrt{19-6\sqrt{2}}-\sqrt{9-4\sqrt{2}}\)

Answer 1

[Nguyễn Quang Trung]

\(=\sqrt{\left(3\sqrt{2}-1\right)^2}-\sqrt{\left(2\sqrt{2}-1\right)^2}\)

\(=3\sqrt{2}-1-2\sqrt{2}+1=\sqrt{2}\)