abc=1,求证: 1/ab+a+1 +1/bc+b+1 +1/ca+c+1 =1

来源:百度知道 编辑:UC知道 时间:2024/06/15 22:53:20

给你一个清晰的过程:

解:
1/(ab+a+1)+1/(bc+b+1)+1/(ca+c+1)
=abc/(ab+a+abc)+1/(bc+b+1)+1/(ca+c+1)······第一项的分子分母的1用abc代替;
=bc/(b+1+bc)+1/(bc+b+1)+1/(ca+c+1)
=(bc+1)/(bc+b+1)+1/(ca+c+1)
=(bc+abc)/(bc+b+abc)+1/(ca+c+1))······第一项的分子分母的1用abc代替;
=(c+ca)/(c+1+ca)+1/(ca+c+1)
=(ca+c+1)/(ca+c+1)
=1

abc=1 1/(ab+a+1)=abc/(ab+a+abc)=bc/(b+1+bc)
1/(ca+c+1)=abc/(ca+c+abc)=ab/(a+1+ab)
=ab/(a+abc+ab)=b/(1+bc+b)
1/ab+a+1 +1/bc+b+1 +1/ca+c+1=1+bc+b/b+1+bc=1