a^2(b-c)+b^2(c-a)+c^2(a-b)
= a^2(b-c)+b^2c-ab^2+ac^2-bc^2
= a^2(b-c)+b^2c-bc^2+ac^2-ab^2
=a^2(b-c)+bc(b-c)+a(c+b)(c-b)
=(b-c)(a^2+bc-ac-ab)
=(b-c)[a(a-b)-c(a-b)]
=(b-c)(a-b)(a-c)
a^2(b-c)+b^2(c-a)+c^2(a-b)
= a^2(b-c)+b^2c-ab^2+ac^2-bc^2
= a^2(b-c)+b^2c-bc^2+ac^2-ab^2
=a^2(b-c)+bc(b-c)+a(c+b)(c-b)
=(b-c)(a^2+bc-ac-ab)
=(b-c)[a(a-b)-c(a-b)]
=(b-c)(a-b)(a-c)