Which are perfect cubes? check all that apply
64
x^16
8x^3
27x^4
81x^6
125x^9

A perfect cube is a number that resulted from multiplying a number three times by itself. A perfect cube is also a number that has an exact cube root.

8x^3 ⇒ 2x^4 * 2x^4 * 2x^4
27x^4 ⇒ 3x³ * 3x³ * 3x³

Only two monomials are perfect cubes.