Question

what is (a+b)(b+c)(a+c) ??

Answer 1

Answer:

Set a+b+c=x

So, we have (x−a)(x−b)(x−c)=x3−x2(a+b+c)+(ab+bc+ca)x−abc

Now, x3−x2(a+b+c)=x2(x−a+b+c¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯)=x2⋅0