From a+b+c=600, A, B and C are all greater than or equal to 0, and B+C-300 =

So we get 2 (b+c-300) 2-2bc+2 * 300 2 =

That's 360000 at most.

A+b+c=600, and A, B and C are all greater than or equal to 0, then the sum of two numbers in A, B and C must be greater than or equal to 300, assuming B+C >; =300,

When the maximum value of a 2+b 2+c 2 is 360000.

-bc is the maximum value, that is, -bc=0, so b=0 or C = 0；;

B+c-300 is the maximum value, that is, b+c-300=300, that is, b+c=600, so a=0.

That is, a=0, b=0, c = 600 or a=0, b=600, c=0.