how to get from step 2 to step 3

1. (x^3 + y^3) + xy(x + y)
2. (x + y)(x^2 - xy + y^2) + xy(x + y)
3. (x + y)(x^2 + y^2)

objective: factorization

2 answers

2. (x + y)(x^2 - xy + y^2) + xy(x + y)
2. a)
= (x + y)(x^2 - xy + y^2 + xy)
x+y was a common factor ...
3. (x + y)(x^2 + y^2)
thank u sooo much !!!! ur a lifesaver :D