Factoring x^3 + y^3 = (x + y)?

Question

I'm in a little need of help with my homework. Does anyone know how to explain this problem to me? Help is much appreciated. Thank you in advance.

Answer 1

x³ + y³ = (x + y)?

Note: We know that (a³ + b³) = (a + b)(a² + ab + b²)

So,

x³ + y³ = (x + y)(x² + xy + y²)

There fore

x³ + y³ = (x + y)(x² + xy + y²)