Tính a) 14/15 : (-7/5); b) (-2 2/5) : (-0,32)

* Hướng dẫn giải

a) $\frac{14}{15}:\left(-\frac{7}{5}\right)=\frac{14}{15}.\left(\frac{-5}{7}\right)=\frac{14.(-5)}{15.7}=\frac{-2}{3}$

b) $\left(-2\frac{2}{5}\right):(-0,32)=\left(\frac{-12}{5}\right):\left(\frac{-32}{100}\right)$

$=\left(\frac{-12}{5}\right):\left(\frac{-8}{25}\right)=\frac{(-12).25}{5.(-8)}=\frac{3.5}{2}=\frac{15}{2}$