Hứa vote sao😢😢 e cần gấp ạ

$\sqrt{2}.x-\sqrt{8}=\sqrt{18}$

$↔\sqrt{2}.x-2\sqrt{2}=3\sqrt{2}$

$↔\sqrt{2}.x=3\sqrt{2}+2\sqrt{2}$

$↔\sqrt{2}.x=5\sqrt{2}$

$↔x=5\sqrt{2}:\sqrt{2}$

$↔x=5$

Vậy $x=5$