3. Equivalent to proof

(a^3+b^3+c^3)^2<； (a^2+b^2+c^2)^3

Might as well set up a> = b> = C.

Open the inequality and eliminate A 6, B 6 and C 6.

2a 3b 3 is on the left.

2a 3c 3 is on the left.