Question

a) 5^-1 - 2^-2
b) (1/3) ^-2 - (1/4)^-1
c) 6^-2 : 6^0
d) (1/2)^3 . (1/2)^-2

Answer 1

Lembre que $a^{-b} = \frac{1}{ a^{b} }$
A)$5^{-1} - 2^{-2} = \frac{1}{5} - \frac{1}{ 2^{2} } = \frac{1}{5} - \frac{1}{4} = \frac{4}{20} - \frac{5}{20} = - \frac{1}{20}$
B)$( \frac{1}{3} ) ^{-2} - (\frac{1}{4})^{-1} = \frac{3^{2} }{1} - 4 = 9 - 4 = 5$
C)$\frac{6^{-2} }{ 6^{0} } = \frac{ \frac{1}{ 6^{2} } }{1} = \frac{1}{36}$
D)$(\frac{1}{2})^{3} \times ( \frac{1}{2})^{-2} = \frac{1}{8}\times \frac{4}{1} = \frac{1}{2}$