Calculati
[tex] - \frac{25}{39} - ( \frac{18}{39} )[/tex]

[tex] \frac{7}{12} + \frac{5}{12} [/tex]

[tex] \frac{21}{14} - \frac{9}{14} [/tex]

[tex] \frac{5}{8} + \frac{3}{4} [/tex]

[tex] - \frac{11}{12} + \frac{11}{20} [/tex]

[tex] \frac{8}{9} - \frac{8}{15} [/tex]

[tex] \frac{29}{47} + ( - \frac{31}{47} )[/tex]

[tex] \frac{7}{16} - ( - \frac{11}{12} )[/tex]

[tex] - \frac{14}{21} + ( - \frac{15}{28} )[/tex]

ajutaţi va rog !!!
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