x(y2−z2)+y(z2−x2)+z(x2−y2)=xy2−xz2+yz2−yx2+zx2−zy2 Arrange the terms in descending order of power of x. =−x2y+zx2+xy2−xz2−yz+yz2 =−x2(y−z)+x(y2−z2)−yz(y−z) =−x2(y−z)+x(y−z)(y+z)−yz(y−z) =(y−z)[−x2+x(y+z)−yz] (y−z)[−x2+xy+xz−yz]
Arrange the term in bracket in descending order of the power of y. =(y−z)[xy−yz−x2+xz] =(y−z)[−y(−x+z)+x(−x+z)] =(x−y)(y−z)(z−x).