Verified answer

Two well known formulae are:

a^3 + b^3 = (a + b)(a^2 - ab + b^2)

a^3 - b^3 = (a - b)(a^2 + ab + b^2)

Here we have :

y^3 - 8

From inspection you can see that:

y^3 - 8 = y^3 - 2^3

Using y = a, b = 2

y^3 - 8 = (y - 2)(y^2 + 2y + 4)