x3 + y3 + 3xy(x + y)(x + y)2 - 4xy ÷ (x - y)2 + 4xyx3 - y3 - 3xy(x -y)

Answer: 
x2 - y2
x3 + y3 + 3xy(x + y)(x + y)2 - 4xy ÷ (x - y)2 + 4xyx3 - y3 - 3xy(x -y)