Question

задание по математике вычислите

Answer 1

а).

$\tt (-4)^{-3}=-\dfrac{1}{4^{3}}=-\dfrac{1}{4\cdot4\cdot4}=\bf -\dfrac{1}{64}$

б).

$\tt 2,5^{-1}=\Big(\dfrac{25}{10}\Big)^{-1}=\Big(\dfrac{5}{2}\Big)^{-1}=\dfrac{2}{5}=\bf 0,4$

в).

$\tt \Big(-\dfrac{3}{4}\Big)^{-2}=\Big(-\dfrac{4}{3}\Big)^2=\dfrac{4^2}{3^2}=\dfrac{4\cdot4}{3\cdot3}=\dfrac{16}{9}=\bf 1\dfrac{7}{9}$

г).

$\tt \Big(1\dfrac{1}{3}\Big)^{-3}=1:\Big(1\dfrac{1}{3}\Big)^3=1:\dfrac{4^3}{3^3}=1\cdot\dfrac{27}{64}=\bf \dfrac{27}{64}$

д).

$\tt -0,4^{-4}=-\Big(\dfrac{4}{10}\Big)^{-4}=-\Big(\dfrac{5}{2}\Big)^4=-\Big(\dfrac{5^4}{2^4}\Big)=-\dfrac{625}{16}=\bf -39\dfrac{1}{16}$

е).

$\tt -\Big(2\dfrac{1}{2}\Big)^{-2}=-1:\dfrac{5^2}{2^2}=-1:\dfrac{25}{4}=-1\cdot\dfrac{4}{25}=-\dfrac{4}{25}=\bf -0,16$