Suppose a,b,ca, b, ca,b,c are the sides of a triangle. Prove that a2(b+c−a)+b2(c+a−b)+c2(a+b−c)≤3abc.a^2(b + c - a) + b^2(c + a - b) + c^2(a + b - c) \leq 3abc.a2(b+c−a)+b2(c+a−b)+c2(a+b−c)≤3abc.