7 Вычислите: а) \(-\frac{3}{10} : \frac{3}{5}\); б) −4⋅(−0,8); в) \((-\frac{1}{2})^3\).

1. а) − \(\frac{3}{10}\) : \(\frac{3}{5}\) = − \(\frac{3}{10}\) ⋅ \(\frac{5}{3}\) = − \(\frac{15}{30}\) = − \(\frac{1}{2}\)
2. б) −4 ⋅ (−0,8) = 3,2
3. в) \((-\frac{1}{2})^3\) = − \(\frac{1}{2}\) ⋅ (− \(\frac{1}{2}\)) ⋅ (− \(\frac{1}{2}\)) = − \(\frac{1}{8}\)

Ответ: а) − \(\frac{1}{2}\); б) 3,2; в) − \(\frac{1}{8}\)