>>100
(a+b)(b+c)(c+a)+abc
= (b+c) { (a^2) +(b+c)a+bc} + abc
= (b+c) (a^2) + ((b+c)^2 +bc)a + (b+c)bc
= (a +b+c){(b+c)a+bc}
= (a+b+c)(ab+bc+ca)