Gọi \(\frac{a}{x}=m,\frac{b}{y}=n,\frac{c}{z}=p\)
Ta có :
m+n+p = 2
Và \(\frac{1}{m}+\frac{1}{n}+\frac{1}{p}=0\)
\(\Leftrightarrow\frac{np}{mnp}+\frac{mp}{mnp}+\frac{mn}{mnp}\) = 0
\(\Leftrightarrow\)\(\frac{np+mp+mn}{mnp}\) = 0
\(\Rightarrow\) \(np+mp+mn=0\)
Mà \(m+n+p=2\Leftrightarrow\left(m+n+p\right)^2=2^2=4\)
\(\Leftrightarrow m^2+n^2+p^2+2np+2mp+2mn\) =4
\(\Leftrightarrow m^2+n^2+p^2+2\left(np+mp+mn\right)\) =4
\(\Leftrightarrow m^2+n^2+p^2+2.0=m^2+n^2+p^2=4\)
\(\Rightarrow\)........