Răspuns:
[tex]\boxed{x\in (-\infty, -6)}[/tex]
Explicație pas cu pas:
[tex]\sqrt 2 x-\sqrt{72} >x\sqrt 8 \\\\ \sqrt 2 x- x\sqrt 8 > \sqrt{72} \\\\ \sqrt 2 x - x\sqrt{2^2\cdot 2}>\sqrt{3^2\cdot 2^2\cdot 2}\\ \\ \sqrt 2 x-x\cdot 2\sqrt 2 > 3\cdot 2\cdot \sqrt{2} ~\Big|:\sqrt 2\\ \\ x - 2x > 6 \\\\ -x>6\\\\ x<-6\\ \\ \Rightarrow x\in (-\infty, -6)[/tex]
