Resposta :
a) Temos que:
[tex]\dfrac{3}{5}\times\left(\dfrac{1}{3}-\dfrac{1}{2}\right)[/tex]
[tex]=\dfrac{3}{5}\times\left(\dfrac{2-3}{6}\right)[/tex]
[tex]=\dfrac{3}{5}\times\dfrac{-1}{6}=\dfrac{-3}{30}=\dfrac{-1}{10}[/tex]
b) Temos que:
[tex]\dfrac{-2}{9}\times\left(\dfrac{1}{4}+\dfrac{1}{5}\right)[/tex]
[tex]=\dfrac{-2}{9}\times\left(\dfrac{5+4}{20}\right)[/tex]
[tex]=\dfrac{-2}{9}\times\dfrac{9}{20}=\dfrac{-18}{180}=\dfrac{-1}{10}[/tex]
c) Temos que:
[tex]\dfrac{2}{5}-\dfrac{8}{3}\times\left(\dfrac{1}{2}\right)^3+\dfrac{3}{4}[/tex]
[tex]=\dfrac{2}{5}-\dfrac{8}{3}\times\dfrac{1}{8}+\dfrac{3}{4}[/tex]
[tex]=\dfrac{2}{5}-\dfrac{1}{3}+\dfrac{3}{4}[/tex]
[tex]=\dfrac{24-20+45}{60}=\dfrac{49}{60}[/tex]
d) Temos que:
[tex]\dfrac{-7}{9}\times\left(\dfrac{2}{3}-\dfrac{4}{5}\times5\right)[/tex]
[tex]=\dfrac{-7}{9}\times\left(\dfrac{2}{3}-4\right)[/tex]
[tex]=\dfrac{-7}{9}\times\left(\dfrac{2-12}{12}\right)[/tex]
[tex]=\dfrac{-7}{9}\times\dfrac{-10}{12}[/tex]
[tex]=\dfrac{70}{108}=\dfrac{35}{54}[/tex]