Resposta:
[tex]a)\\ \\ \dfrac{4}{8}\times\dfrac{6}{8}=\\ \\ \\ simplifique\\ \\ \dfrac{\not4^1}{\not8_2}\times\dfrac{\not6^3}{\not8_4}=\dfrac{1}{2}\times\dfrac{3}{4}}=\dfrac{3}{8}[/tex]
b)
[tex]\dfrac{3}{4}\div\dfrac{1}{4}=\\ \\ \\ \dfrac{3}4}\times\dfrac{4}{1}=\dfrac{12}{4}=3[/tex]
c)
[tex]\dfrac{2}{6}+\dfrac{5}{6}=\dfrac{7}{6}[/tex]
d)
[tex]\dfrac{10}{9}-\dfrac{2}{9}=\dfrac{8}{9}[/tex]
