Выполните действия: a) -23⋅5; б) - \frac{4}{7}⋅(- \frac{1}{2}); в) 3 \frac{2}{3}⋅(- \frac{4}{11}); г) -0,6⋅0,2; д) (-\frac{1}{3})^2; e) (-2)³; ж) -2,4⋅(-5); з) (\frac{1}{5} - \frac{3}{4})⋅(-4); и) (-0,4 – 0,3)⋅(-7).

Ответ:

• a) \[ -23 \cdot 5 = -115 \]
• б) \[ -\frac{4}{7} \cdot\left(-\frac{1}{2}\right) = \frac{4 \cdot 1}{7 \cdot 2} = \frac{4}{14} = \frac{2}{7} \]
• в) \[ 3 \frac{2}{3} \cdot\left(-\frac{4}{11}\right) = \frac{3 \cdot 3 + 2}{3} \cdot\left(-\frac{4}{11}\right) = \frac{11}{3} \cdot\left(-\frac{4}{11}\right) = -\frac{11 \cdot 4}{3 \cdot 11} = -\frac{4}{3} = -1 \frac{1}{3} \]
• г) \[ -0.6 \cdot 0.2 = -0.12 \]
• д) \[ \left(-\frac{1}{3}\right)^2 = \left(-\frac{1}{3}\right) \cdot\left(-\frac{1}{3}\right) = \frac{1}{9} \]
• е) \[ (-2)^3 = (-2) \cdot (-2) \cdot (-2) = 4 \cdot (-2) = -8 \]
• ж) \[ -2.4 \cdot (-5) = 12 \]
• з) \[ \left(\frac{1}{5} - \frac{3}{4}\right) \cdot (-4) = \left(\frac{4}{20} - \frac{15}{20}\right) \cdot (-4) = \frac{-11}{20} \cdot (-4) = \frac{11 \cdot 4}{20} = \frac{44}{20} = \frac{11}{5} = 2 \frac{1}{5} \]
• и) \[ (-0.4 - 0.3) \cdot (-7) = (-0.7) \cdot (-7) = 4.9 \]

Ответ: