Дроби с минусом

[Гость]

(-7/9+4/5)÷(-7/10)=

[Andy]

(-7/9+4/5)÷(-7/10)=

[tex]\frac{\left( -\frac{7}{9}+\frac{4}{5}\right)}{\frac{-7}{10}}=\left( -\frac{7}{9}+\frac{4}{5}\right) \cdot \left( -\frac{10}{7} \right)=\frac{-35+36}{45} \cdot \left( -\frac{10}{7} \right)=\frac{1}{45} \cdot \left( -\frac{10}{7} \right)=-\frac{2}{63}.[/tex]