Question

Calcule as potências a seguir:
a) -4 elevado a -2
b) (-5/2)elevado a -2
c) 7 elevado a -2
d) (1/10) elevado a -5
e) -(0,3) elevado a -5

Answer 1

$a) ( -4)^{-2} = \frac{1}{ (-4)^{2} } = \frac{1}{16} \\ \\ \\ b) (-\frac{5}{2}) ^{-2} = \frac{x}{ (- \frac{5}{2} )^{2} } =\frac{x}{ ( \frac{5}{2} )^{2} }= \frac{1}{ \frac{5^2}{2^2} } = \frac{1}{ \frac{25}{4} } = \frac{4}{25} \\ \\ \\ \\ c) 7^{-2} = \frac{1}{7^2} = \frac{1}{49} \\ \\ \\ \\ d) ( \frac{1}{10}) ^{-5} = (\frac{10}{1} )^{5} = \frac{10^5}{1^5} =10^5=10000 \\ \\ \\ \\ e)- (0,3)^{-5} =- (\frac{3}{10}) ^{-5} =- ( \frac{10}{3}) ^{-5} =- \frac{10^5}{3^5} =- \frac{10000}{243}$