a+1/a=3(a+1/a)^2=a^2+2+1/a^2=9a^2+1/a^2=7a^2/(a^4+a^2+1)=1/(a^2+1+1/a^2)=1/(7+1)=1/8x=a/(b+c),y=b/(c+a),z=c/(a+b)1/x=(b+c)/a1+1/x=(a+b+c)/a(1+x)/x=1+1/x=(a+b+c)/ax/(1+x)=a/(a+b+c)同理y/(1+y)=b/(a+b+c)...