271)
$\small \left\{\left[\left(\dfrac{1}{4}\right)^3·\left(\dfrac{2}{3}\right)^3\right]^{-1}·\left(\dfrac{1}{6}\right)^4\right\}^{-1} : \left[\left(\dfrac{1}{4}\right)^3·\left(\dfrac{2}{5}\right)^3\right]^0 = $
tutto ciò che è all'interno della parentesi quadra a destra, essendo elevato a zero, diventa uno, quindi:
$\small = \left\{\left[\left(\dfrac{2}{12}\right)^3\right]^{-1}·\left(\dfrac{1}{6}\right)^4\right\}^{-1} : 1= $
$\small = \left\{\left(\dfrac{\cancel2^1}{\cancel{12}_6}\right)^{3·(-1)}·\dfrac{1}{1296}\right\}^{-1} = $
$\small = \left\{\left(\dfrac{1}{6}\right)^{-3}·\dfrac{1}{1296}\right\}^{-1} = $
$\small = \left\{6^3·\dfrac{1}{1296}\right\}^{-1} = $
$\small = \left\{\cancel{216}^1·\dfrac{1}{\cancel{1296}_6}\right\}^{-1} = $
$\small = \left\{\dfrac{1}{6}\right\}^{-1} = $
$\small = 6^1 = $
$\small = 6 $