64=4^3=(1/4)^-3
sper ca te-am ajutat
[tex]\it \Big(\dfrac{1}{4}\Big)^x=64\Rightarrow (4^{-1})^x =4^3 \Rightarrow 4^{-x}=4^3 \Rightarrow -x=3|_{\cdot(-1)} \Rightarrow x=-3[/tex]
