Răspuns :

1.

[tex] \frac{13}{7} + \frac{10}{7} - \frac{9}{7} = \frac{23}{7} - \frac{9}{7} = \frac{14}{7} = 14 \div 7 = 2[/tex]

2.

[tex] \frac{4}{5} + \frac{3}{2} = \frac{8}{10} + \frac{15}{10} = \frac{23}{10} [/tex]

3.

[tex]2 + \frac{3}{4} - \frac{1}{5} = \frac{2}{1} + \frac{3}{4} - \frac{1}{5} = \frac{8}{4} + \frac{3}{4} - \frac{1}{5} = \frac{11}{4} - \frac{1}{5} = \frac{55}{20} - \frac{4}{20} = \frac{51}{20} [/tex]

4.

[tex] \frac{10}{21} \times \frac{9}{2} \times \frac{7}{3} = \frac{90}{42} \times \frac{7}{3} = \frac{630}{126} = \frac{105}{21} = \frac{35}{7} = \frac{5}{1} = 5[/tex]

5.

[tex] \frac{4}{3} \div 2 \times \frac{2}{3} = \frac{4}{3} \div \frac{2 \times 3 + 2}{3} = \frac{4}{3} \div \frac{6 + 2}{3} = \frac{4}{3} \div \frac{8}{3} = \frac{4}{3} \times \frac{3}{8} = \frac{1}{1} \times \frac{1}{2} = \frac{1}{2} = 1 \div 2 = 0.5[/tex]

6.

[tex] ( \frac{11}{7} + \frac{3}{5} ) \div \frac{76}{35} = ( \frac{55}{35} + \frac{21}{35} ) \div \frac{76}{35} = \frac{76}{35} \div \frac{76}{35} = 1[/tex]