Краткий ответ для упражнения № 96:
- \(-\dfrac34\);
- \(15\);
- \(\dfrac{82}{9}\);
- \(100000\);
- \(\dfrac{45}{64}\);
- \(\dfrac{81}{256}\).
Используем правила: \[ a^{-n}=\frac1{a^n},\qquad a^{\frac mn}=\left(\sqrt[n]{a}\right)^m. \]
1)
\[ \frac34-\left(\frac23\right)^{-1} =\frac34-\frac32 =\frac34-\frac64 =-\frac34. \]
2)
\[ \left(\frac1{27}\cdot125^{-1}\right)^{-\frac13} = \left(\frac1{3^3}\cdot\frac1{5^3}\right)^{-\frac13} = \left(\frac1{15^3}\right)^{-\frac13} =15. \]
3)
\[ 27^{\frac23}+9^{-1} =\left(\sqrt[3]{27}\right)^2+\frac19 =3^2+\frac19 =9+\frac19 =\frac{82}{9}. \]
4)
\[ (0{,}01)^{-2}:100^{-\frac12} =(10^{-2})^{-2}:(10^2)^{-\frac12} =10^4:10^{-1} =10^5 =100000. \]
Проверка: \[ 100000\cdot100^{-\frac12}=100000\cdot\frac1{10}=10000=(0{,}01)^{-2}. \]
5)
\[ \left(\frac{64}{81}\right)^{-\frac12}\cdot \left(\frac85\right)^{-1} = \frac1{\sqrt{\frac{64}{81}}}\cdot\frac58 = \frac98\cdot\frac58 =\frac{45}{64}. \]
6)
Сначала представим смешанное число: \[ 2\frac{10}{27}=\frac{64}{27}=\left(\frac43\right)^3. \]
Тогда \[ \left(2\frac{10}{27}\right)^{-\frac23}\cdot \left(\frac34\right)^2 = \left(\left(\frac43\right)^3\right)^{-\frac23} \cdot\left(\frac34\right)^2 \] \[ = \left(\frac43\right)^{-2}\cdot\left(\frac34\right)^2 = \left(\frac34\right)^2\cdot\left(\frac34\right)^2 = \left(\frac34\right)^4 =\frac{81}{256}. \]
