I think a non- integer rational number but I’m not real sure on that.
First, note that 
Then use the formula for the sum of perfect cubes:
Therefore,
The quadratic trinomial 
couldn't be factored anymore, so the expression 
has two factors 
and 
Answer: correct choice is A.
Answer:
y^3/(27 x^3)
Step-by-step explanation:
Simplify the following:
((3 x)/y)^(-3)
((3 x)/y)^(-3) = (y/(3 x))^3:
(y/(3 x))^3
Multiply each exponent in y/(3 x) by 3:
(y^3)/((3 x)^3)
Multiply each exponent in 3 x by 3:
y^3/(3^3 x^3)
3^3 = 3×3^2:
y^3/(3×3^2 x^3)
3^2 = 9:
y^3/(3×9 x^3)
3×9 = 27:
Answer: y^3/(27 x^3)
