Questão 1
[tex]\bullet \ 0,666... = \frac{6}{9} \rightarrow (\frac{6}{9})^2 = \frac{6^2}{9^2} = \frac{36}{81} = \boxed{\frac{4}{9}}[/tex]
Questão 2
[tex]\bullet \ \frac{a}{b} = 2,030303... = \boxed{\frac{201}{99}}[/tex]
Questão 3
[tex]\bullet \ 0,999... + \frac{\frac{1}{5} + \frac{1}{3}}{\frac{3}{5} - \frac{1}{5}} = \frac{9}{9} + \frac{\frac{3 + 5}{15}}{\frac{2}{5}} = 1 + \frac{8}{15} : \frac{2}{5} = 1 + \frac{8}{15} \cdot \frac{5}{2} = \\\\ 1 + \frac{40}{30} = \frac{70}{30} = \boxed{\frac{7}{3}}[/tex]
