could nt get thisproblem=
(a-b)3 +(b-c)3 (c-a)3
(a-b)3 + (b-c)3 + (c-a)3 = a3 - b3 - 3ab(a-b) + b3 - c3 - 3bc(b-c) + c3 - a3 - 3ca(c-a)
= - 3a2b + 3ab2 - 3b2c + 3bc2 - 3ac2 + 3 a2c = 3 (- a2b + ab2 - b2c + bc2 - ac2 + a2c)
= 3 [(a2(c-b) + (b2(a-c) + (c2(b-a)]