\[\boxed{\mathbf{6.109}}\]
\[\textbf{а)}\ 2 < |a| < 9\]
\[|a| = 3;4;5;6;7;8.\]
\[a = \pm 3;\ \pm 4;\ \pm 5;\ \pm 6;\ \pm 7;\ \pm 8.\ \]
\[\textbf{б)}\ 7,8 < |n| < 13\frac{4}{7}\]
\[|n| = 8;9;10;11;12;13.\]
\[n = \pm 8;\ \pm 9;\ \pm 10;\ \pm 11;\ \pm 12;\ \]
\[\pm 13.\]