x/1+ab+a+x/1+b+bc+x/1+c+ca=20111/(1+ab+a)+1/(1+b+bc)+1/(1+c+ca)=2011/x1/(1+ab+a)+1/(1+b+bc)+1/(1+c+ca)=abc/(abc+ab+a)+1/(1+b+bc)+1/(1+c+ca)=bc/(bc+b+1)+1/(1+b+bc)+1/(1+c+ca)=(bc+1)/(bc+b+1)+1/(1+c+ca)...