AD TC D TS = N có:
[tex]\frac{y+z+1+x+z+2+x+y-3}{x+y+z}=\frac{1}{x+y+z}\\\\ => \frac{2.(x+y+z)}{x+y+z}=\frac{1}{x+y+z} => 2.(x+y+z)=1\\\\ => x+y+z=\frac{1}{2}\\\\ => \frac{y+z+1}{x}=\frac{x+z+2}{y}=\frac{x+y-3}{z}=\frac{1}{\frac{1}{2}}=2\\\\ => y+z+1=2x => x+y+z+1=3x => \frac{1}{2}+1=3x\\\\ => \frac{3}{2}=3x => 6x=3 => x=\frac{1}{2}[/tex]
tính y;z tương tự