[tex] \sqrt{2} x - \sqrt{72} > x \sqrt{8} [/tex]
[tex]x \sqrt{2} - x \sqrt{8} > \sqrt{72} [/tex]
[tex]x \sqrt{2} - x \times 2 \sqrt{2} > 6 \sqrt{2} [/tex]
[tex]x \sqrt{2} - 2x \sqrt{2} > 6 \sqrt{2} [/tex]
[tex] - x \sqrt{2} > 6 \sqrt{2} \: | \div ( - \sqrt{2} )[/tex]
[tex]x < - 6[/tex]
[tex]x \: \in \: ( - \infty , - 6)[/tex]
