Which expression is the completely factored form of x3+8y6 ?
x^3 + 8y^6
We have a sum of cubes here
a^3 + b^3 = (a + b) (a^2 - ab + b^2 )
Let a = ∛x^3 = x and b = ∛ [8y^6] = ∛ 8 * ∛y^6 = 2y^2
So we have
(x + 2y^2 ) ( [x]^2 - x*2y^2 + [2y^2]^2 ) =
(x + 2y^2) ( x^2 - 2xy^2 + 4y^4) ⇒ the first answer