Question

determine o valor numérico cada uma das seguintes expressões

d) (8^-2 x 4^3)^-1

Answer 1

$(8^{-2}.4^{3})^-1 = ( \frac{1}{8^{2}}.4^{3})^{-1} = ( \frac{64}{64}) ^{-1} = (1)^{-1} = 1$

Espero ter ajudado.

Answer 2

$\ \ \ (8^{-2} \times 4^3)^{-1}\\ \\=\big[(2^3)^{-2} \times (2^2)^3\big]^{-1}\\ \\=\big[2^{3\cdot(-2)} \times 2^{2\cdot3}\big]^{-1}\\ \\=\big[2^{-6} \times 2^{6}\big]^{-1}\\ \\=\big[2^{-6+6} \big]^{-1}\\ \\=\big[2^0 \big]^{-1}\\ \\=2^{0\cdot (-1)}\\ \\=2^0\\ \\=1$