adtc dãy tỉ số = nhau ta có
x/y+z+1=y/x+z+1=z/x+y-2=x+y+z=x+y+z/2(x+y+z)=1/2
=> x+y+z =1/2=>x+y=1/2-z
y+z=1/2-x
x+z=1/2-y
thay x+y=1/2-z , y+z=1/2-x, x+z=1/2-y vào x/y+z+1=y/x+z+1=z/x+y-2=1/2
=>x/ 1/2-x+1=1/2 y/ 1/2-y+1=1/2 z/ 1/2-z-2=1/2
x/ 3/2-x=1/2 y/ 3/2-y=1/2 z/ -3/2-z=1/2
2x=3/2-x 2y=3/2-y 2z=-3/2-z
x=1/2 y=1/2 z=1/2