Remember what a negative exponent means ... it's just a positive exponent
in the denominator of a fraction. 'x' to negative 3rd power is the same as 1/x³ .
1/x³ = 27/64
Take the reciprocal of each side:
x³ = 64/27
x= ∛64/27 = ∛64 / ∛27.
64 is the perfect cube of 4.
27 is the perfect cube of 3.
x = 4/3 .