Tìm X :
X - 4 = căn ( 3 - 2 căn 2 )
Kasamita <3
$ x - 4 = \sqrt{3 - 2\sqrt{2}} \\ \Leftrightarrow x - 4 = \sqrt{2 - 2\sqrt{2} + 1} \\ \Leftrightarrow x - 4 = \sqrt{(\sqrt{2} - 1)^2} \\ \Leftrightarrow x - 4 = |\sqrt{2} - 1| \\ \Leftrightarrow x - 4 = \sqrt{2} - 1 \\ \Leftrightarrow x = 3 + \sqrt{2} $