\(\Leftrightarrow\left(\frac{x-b-c}{a}-1\right)+\left(\frac{x-c-a}{b}-1\right)+\left(\frac{x-a-b}{c}-1\right)=0\\ \)
\(\Leftrightarrow\left(x-p\right)\left(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\right)=0\)
=> x=p=(a+b+c)
\(\frac{x-b-c}{a}+\frac{x-c-a}{b}+\frac{x-a-b}{c}=3\)
\(\frac{x-b-c}{a}-1+\frac{x-c-a}{b}-1+\frac{x-a-b}{c}-1=0\)
\(\frac{x-a-b-c}{c}+\frac{x-a-b-c}{b}+\frac{x-a-b-c}{a}=0\)
\(\left(x-a-b-c\right)\left(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\right)=0\)
Cọn lại tự giải nha
\(\frac{x-b-c}{a}+\frac{x-c-a}{b}+\frac{x-a-b}{c}=3\)
\(\Rightarrow\frac{x-b-c-a}{a}+\frac{x-a-b-c}{b}+\frac{x-a-b-c}{c}=0\)
\(\Rightarrow\left(x-a-b-c\right)\left(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\right)=0\)
Với \(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=0\)=> vô số nghiệm
Với \(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\ne0\Rightarrow x=a+b+c\Leftrightarrow S=\left\{a+b+c\right\}\)