Răspuns:
[tex]( \frac{11}{12} - \frac{13}{18} ) \div 7 = \\ (\frac{33}{36} - \frac{26}{36} ) \div 7 = \\ \frac{7}{36} \div \frac{7}{1} = \frac{1}{36} [/tex]
Am amplificat fractia 11/12 cu 3 si 13/18 cu 2.