7-
a[tex]10^{-2} = \frac{1}{10}^{2} = \frac{1}{10} .\frac{1}{10} = \frac{1}{100}[/tex])
b) [tex](\frac{-5}{8})^{-2} = (\frac{-8}{5})^2 = (\frac{-8}{5}) . (\frac{-8}{5}) = \frac{64}{25}[/tex]
c) [tex](\frac{-3}{2})^{-3} = (\frac{-2}{3})^{3} = (\frac{-2}{3}) . (\frac{-2}{3}) . (\frac{-2}{3}) = (\frac{-8}{27})[/tex]
d) [tex](-3)^{-3} = (\frac{-1}{3})^{3} = (\frac{-1}{3}) . (\frac{-1}{3}) .(\frac{-1}{3}) =(\frac{-1}{27})[/tex]
e) [tex](\frac{2}{3})^{-2} = \frac{3}{2}^2 = \frac{3}{2} . \frac{3}{2} = \frac{9}{4}[/tex]
f) [tex](\frac{1}{2})^{-5} = (\frac{2}{1})^5 = \frac{2}{1} . \frac{2}{1} . \frac{2}{1} . \frac{2}{1} .\frac{2}{1} =\frac{32}{1} = 32[/tex]
8- Desafio:
[tex]- (-1)^{3} - (-1)^{4} + (-2)^{2} -2^{3} + (-1 -1)^{2} = \\1^3 + 1^4 + (-2)^2 - 2^3 + (-2)^2=\\1 + 1 + 4 - 8 + 4 =\\2[/tex]
