Factories:
y2 – xy(1 – x) – x3
= y2 – xy + x2y – x3
= (y2 – xy) + (x2y – x3)
= y(y – x) + x2(y – x)
= (y –x)(y + x2)
So we get,
y2 – xy(1 – x) – x3 = (y –x)(y + x2)