Explicação passo-a-passo:
[tex]a)[/tex]
[tex] \dfrac{3}{5} \div \dfrac{3}{4} [/tex]
[tex] \dfrac{3}{5} \times \dfrac{4}{3} [/tex]
[tex] \dfrac{12}{15} [/tex]
[tex] \dfrac{12 {}^{ \div 3} }{15 {}^{ \div 3} } [/tex]
[tex] \dfrac{4}{5} [/tex]
[tex]b)[/tex]
[tex] \dfrac{3}{5} \div - \dfrac{2}{7} [/tex]
[tex] \dfrac{3}{5} \times - \dfrac{7}{2} [/tex]
[tex] - \dfrac{21}{10} [/tex]
[tex]c)[/tex]
[tex] - \dfrac{4}{9 } \div - \dfrac{5}{2} [/tex]
[tex] \dfrac{4}{9} \times \dfrac{2}{5} [/tex]
[tex] \dfrac{8}{45} [/tex]
[tex]d)[/tex]
[tex] - \dfrac{5}{6} \div - \dfrac{1}{4} [/tex]
[tex] \dfrac{5}{6} \times \dfrac{4}{1} [/tex]
[tex] \dfrac{20}{6} [/tex]
[tex] \dfrac{20 {}^{ \div 2} }{6 {}^{ \div 2} } [/tex]
[tex] \dfrac{10}{3} [/tex]
[tex]e)[/tex]
[tex] - 4 \div \dfrac{8}{3} [/tex]
[tex] - 4 \times \dfrac{3}{8} [/tex]
[tex] - \dfrac{12}{8} [/tex]
[tex] - \dfrac{12 {}^{ \div 2} }{8 {}^{ \div 2} } [/tex]
[tex] - \dfrac{6}{4} [/tex]
[tex] - \dfrac{6 {}^{ \div 2} }{4 {}^{ \div 2} } [/tex]
[tex] - \dfrac{3}{2} [/tex]
[tex]f)[/tex]
[tex] - 6 \div 5[/tex]
[tex] - (6 \div 5)[/tex]
[tex] - 1.2[/tex]
