Question

O Valor da Expressão (256)^-3/4 é

Answer 1

pra muda o sinal do expoente basta vc inverte a fraçao.

$=256^{- \frac{3}{4}} \\ \\= (2^8)^{ -\frac{3}{4}} \\ \\ =2^{- \frac{24}{4}} \\ \\ =2^{-6} \\ \\ =( \frac{1}{2})^6 \\ \\ = \frac{1^6}{2^6} \\ \\ = \frac{1}{64}$

Answer 2

$Resolu\c{c}\~ao \to \left\{\begin{array}{ccc}256^{- \frac{3}{4} }=\\\\ \frac{1}{256^{ \frac{3}{4} }}=\\\\ \frac{1}{(2^8)^{ \frac{3}{4} }}=\\\\ \frac{1}{2^{ \frac{24}{4} }}=\\\\ \frac{1}{2^6}=\\\\ \boxe{\boxed{=\frac{1}{64}}} \end{array}\right$

Espero ter ajudado. :))