已知A+B+C=0,求证A的平方+B的平方+C的平方/A的立方+B的立方+C的立方+2/3(1/a+1/b+1/c)=0

A+B+C=0C=-(A+B)(A^2+B^2+C^2) / (A^3+B^3+C^3) + 2/3(1/A+1/B+1/C) = (A^2+B^2+(-A-B)^2) / (A^3+B^3+(-A-B)^3) + 2/3(1/A+1/B+1/(-A-B) = (A^2+B^2+(-A-B)^2) / (A^3+B^3+(-A-B)^3) + 2/3(1/A+1/B-1/(A+B) )= (2A^...