\[\sqrt{23} - \sqrt{27}\ \ \ и\ \ \ \sqrt{35} - \sqrt{34}\ \]
\[\sqrt{23} - \sqrt{27} < 0;\ \ \]
\[\sqrt{35} - \sqrt{34} > 0\ \]
\[\Longrightarrow \sqrt{23} - \sqrt{27} < \sqrt{35} - \sqrt{34}.\]