\[\frac{m^{2} + 10m}{9 - m^{2}} - \frac{4m - 9}{9 - m^{2}} =\]
\[= \frac{m^{2} + 10m - 4m + 9}{9 - m^{2}} =\]
\[= \frac{m^{2} + 6m + 9}{- \left( m^{2} - 9 \right)} =\]
\[= - \frac{m + 3}{m - 3} = \frac{m + 3}{3 - m}\]