\[\boxed{\mathbf{744\ (744)}.\ Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ \frac{5}{19} + \frac{6}{19} = \frac{5 + 6}{19} = \frac{11}{19}\]
\[2)\ \frac{7}{13} - \frac{4}{13} = \frac{7 - 4}{13} = \frac{3}{13}\]
\[3)\ \frac{19}{25} + \frac{4}{25} - \frac{22}{25} =\]
\[= \frac{19 + 4 - 22}{25} = \frac{1}{25}\]
\[4)\ \frac{34}{39} - \frac{15}{39} - \frac{8}{39} =\]
\[= \frac{34 - 15 - 8}{39} = \frac{11}{39}\]