\(x\sqrt{18}-\sqrt{18}=x\sqrt{18}+4\sqrt{2}\\ \Rightarrow-3\sqrt{2}=4\sqrt{2}\left(vô.lí\right)\)
\(x\sqrt{18}-\sqrt{18}=x\sqrt{18}+4\sqrt{2}.\)
\(\Leftrightarrow x\sqrt{18}-\sqrt{18}-x\sqrt{18}=4\sqrt{2}.\)
\(\Leftrightarrow-3\sqrt{2}=4\sqrt{2}\) (vô lý).
<=> x\(\sqrt{18}\) - x\(\sqrt{18}\) = \(4\sqrt{2}\) + \(\sqrt{18}\)
<=> 0x = \(4\sqrt{2}\) + \(3\sqrt{2}\)
<=>0x = \(7\sqrt{2}\)