If (aa+ab+bb)=(bb+bc+cc) and a,b,c are not equal to each other than a+b+c=????
Statement is as= a^2+ab+b^2=b^2+bc+c^2 then cancel bsqare with L.h.s &R.h.s u got a^2-c^2=bc-ab after solve it a+b+c=0
They are claiming zero because, after subtracting the common BB term from each side, you are left with A(A+B)=C(C+B). After some manipulation, you get:
Since A=/=C, A+B+C must equal zero.