Răspuns :
[tex] \frac{7}{10} + \frac{2}{12} = amplificam \frac{7}{10} cu 12 iar \frac{2}{12} cu 10 = \frac{84}{120} + \frac{20}{120} = \frac{104}{120} [/tex] simplificam prin 4 = [tex] \frac{26}{30} [/tex] simplificam prin 2 =[tex] \frac{13}{15} [/tex]