Resposta:

a)

[tex] \frac{27}{12} + \frac{31}{12} = \frac{29}{6} [/tex]

b)

[tex] \frac{7}{14} - \frac{2}{77} = \frac{73}{154} [/tex]

c)

[tex] \frac{3}{5} + \frac{2}{4} - \frac{1}{3} = \frac{23}{30} [/tex]

d)

[tex] \frac{9}{8} \times \frac{8}{9} = 1[/tex]

e)

[tex] - \frac{11}{4} \times \frac{13}{6} = - \frac{143}{24} [/tex]

f)

[tex] \frac{12}{13} \div \frac{7}{8} = \frac{96}{91} \\ \\ g ) \frac{7}{5} \div 6 = \frac{7}{30} \\ \\ h) \frac{11}{} \times \frac{33}{8} = \frac{363}{8} [/tex]

[tex]j) \frac{7}{5} - \frac{2}{3} + \frac{1}{7} = \frac{92}{105} [/tex]

[tex]i) = \frac{2}{3} \times \frac{1}{7} \times \frac{5}{2} = \frac{5}{21} [/tex]