Să se calculeze:

[tex] \frac{1}{5} + \frac{2}{5} = \\\\ \frac{2}{17} + \frac{3}{17} + \frac{9}{17} = \\ \\
\frac{5}{6} - \frac{2}{6} = \\\\ \frac{19}{25} - \frac{2}{25} - \frac{1}{25} = [/tex]

va rog ​