Question 446626

27^(-2/3) = 1/(27^(2/3))
The denominator 27^(2/3) is the cube root of 27^2.
27^2 = 729
The cube root of 729 is ???
Using the Google calculator:  729^(1/3) = 9
So,
27^(-2/3) = 1/9
Done.