原表述有误.应为:
已知三个正数a、b、c,满足abc=1.求a/(ab+a+1 )+b/(bc+b+1)+c/(ac+c+1).
a/(ab+a+1 )+b/(bc+b+1)+c/(ac+c+1)
=a/(ab+a+abc )+b/(bc+b+1)+c/(ac+c+abc)
=1/(b+1+bc)+b/(bc+b+1)+(bc)/(abc+bc+b)
=1/(b+1+bc)+b/(bc+b+1)+(bc)/(1+bc+b)
=(1+bc+b)/(1+bc+b)
=1.
原表述有误.应为:
已知三个正数a、b、c,满足abc=1.求a/(ab+a+1 )+b/(bc+b+1)+c/(ac+c+1).
a/(ab+a+1 )+b/(bc+b+1)+c/(ac+c+1)
=a/(ab+a+abc )+b/(bc+b+1)+c/(ac+c+abc)
=1/(b+1+bc)+b/(bc+b+1)+(bc)/(abc+bc+b)
=1/(b+1+bc)+b/(bc+b+1)+(bc)/(1+bc+b)
=(1+bc+b)/(1+bc+b)
=1.