Question 396980
{{{(a-b)(a^3+a^2b+ab^2+b^3)}}}.........group elements in second ( ....)

{{{(a-b)((a^3+a^2b)+(ab^2+b^3))}}}.........


{{{(a-b)(a^2(a+b)+b^2(a+b))}}}.........common {{{a+b}}}

{{{(a-b)((a+b)(a^2+b^2))}}}.......

{{{(a-b)(a+b)(a^2+b^2)}}}.......