已知 abc=1, 求a/(ab+a+1)+b/(bc+b+1)+c/(ca+c+1)的值

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已知 abc=1, 求a/(ab+a+1)+b/(bc+b+1)+c/(ca+c+1)的值

已知 abc=1, 求a/(ab+a+1)+b/(bc+b+1)+c/(ca+c+1)的值
已知 abc=1, 求a/(ab+a+1)+b/(bc+b+1)+c/(ca+c+1)的值

已知 abc=1, 求a/(ab+a+1)+b/(bc+b+1)+c/(ca+c+1)的值
abc=1
所以b=1/ac
ab=1/c
bc=1/a
所以原式=a/(1/c+a+1)+(1/ac)/(1/a+1/ac+1)+c/(ac+c+1)
=ac/(ac+c+1)+1/(ac+c+1)+c/(ac+c+1)
=(ac+c+1)/(ac+c+1)
=1

abc=1
所以b=1/ac
ab=1/c
bc=1/a
所以原式=a/(1/c+a+1)+(1/ac)/(1/a+1/ac+1)+c/(ac+c+1)
=ac/(ac+c+1)+1/(ac+c+1)+c/(ac+c+1)
=(ac+c+1)/(ac+c+1)
=1

a/(ab+a+1)
=a/(ab+a+abc)
=1/(bc+b+1)
a/(ab+a+1)
=(ac)/(abc+ac+c)
=(ac)/(ca+c+1)
进行类似变换可得
3[a/(ab+a+1)+b/(bc+b+1)+c/(ca+c+1)]
=a/(ab+a+1)+1/(bc+b+1)+(ac)/(ca+c+1)+b/(bc+...

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a/(ab+a+1)
=a/(ab+a+abc)
=1/(bc+b+1)
a/(ab+a+1)
=(ac)/(abc+ac+c)
=(ac)/(ca+c+1)
进行类似变换可得
3[a/(ab+a+1)+b/(bc+b+1)+c/(ca+c+1)]
=a/(ab+a+1)+1/(bc+b+1)+(ac)/(ca+c+1)+b/(bc+b+1)+1/(ca+c+1)+(ab)/(ab+a+1)+c/(ca+c+1)+1/(ab+a+1)+(bc)/(bc+b+1)
=(ab+a+1)/(ab+a+1)+(bc+b+1)/(bc+b+1)+(ca+c+1)/(ca+c+1)
=1+1+1
=3
a/(ab+a+1)+b/(bc+b+1)+c/(ca+c+1)=1

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1