Tìm x: a) căn ( x- 5 ) = 2
B) căn ( x-1 ) - căn (3-2 căn 2) = 0
Bài $b)$
$\sqrt {x-1}-\sqrt {3-2\sqrt {2}}=0$
$\Leftrightarrow \sqrt {x-1}=\sqrt {3-2\sqrt {2}}$
$\Leftrightarrow x-1=3-2\sqrt {2}$ $($ do $3-2\sqrt{2} > 0)$
$\Leftrightarrow x=3-2\sqrt {2}+1=4-2\sqrt {2}$