Question

Efetue e simplifique quando possível:

a) 5⁻¹ - 5⁻²

b) (-2)⁻³ - 2⁻²​

Answer 1

Resposta:

a)

$5^{-1} - 5^{-2} \\\\= \frac{1}{5} - \frac{1}{5^{2} } \\\\= \frac{1}{5} - \frac{1}{25}\\\\= \frac{5}{25} - \frac{1}{25} \\\\= \frac{4}{25} \\\\ = 0,16$

b)

$(-2)^{-3} - 2^{-2} \\\\= \frac{1}{(-2)^{3} } - \frac{1}{2^{2} } \\\\= \frac{1}{(-2 . -2 . -2)} - \frac{1}{2 . 2}\\\\= \frac{1}{- 8} - \frac{1}{4}\\\\= \frac{1}{-8} - \frac{(-2)}{8}\\\\= \frac{1}{8} \\\\= 0,125$