\[\sqrt{3 + 10m,}\ \ \ \ \ \ \ m \in N\]
\[пусть\ \ \sqrt{3 + 10m} = n,\ \ \ \ \ n \in N\]
\[3 + 10m = n^{2}\]
\[10m = n^{2} - 3 \Longrightarrow m =\]
\[= \frac{n^{2}}{10} - \frac{3}{10}\ \ \notin N.\]