Mathematics
Answer
We use the identity:
x3 + y3 + z3 = 3xyz, if x + y + z = 0
Let (a - b) = x, (b - c) = y and (c - a) = z.
Then, x + y + z = a - b + b - c + c - a = 0
Since the sum is zero, we apply the identity:
⇒ (a - b)3 + (b - c)3 + (c - a)3 = 3(a - b)(b - c)(c - a)
Hence, (a - b)3 + (b - c)3 + (c - a)3 = 3(a - b)(b - c)(c - a).