Question: Find the product:
(x2 + xy + y2) × (x − y)
Solution:
By horizontal method:
$\left(x^{2}+x y+y^{2}\right) \times(x-y)$
$x\left(x^{2}+x y+y^{2}\right)-y\left(x^{2}+x y+y^{2}\right)$
$=x^{3}+x^{2} y+x y^{2}-x^{2} y-x y^{2}-y^{3}$
$=x^{3}-y^{3}$