[tex] \frac{4}{39} - \frac{2}{65} + \frac{3}{26} - \frac{5}{52} [/tex]
Numitorul comun este 780 si aduc fiecare fractie la el:
[tex] \frac{20*4}{780}- \frac{2*12}{780} + \frac{30*3}{780} - \frac{15*5}{780} =
\frac{80+24+90-75}{780} = \frac{119}{780} [/tex]
