$$\left. \begin{array} { l } { x } \\ { x ^ { 2 } - 5 x + 6 = 0 } \\ { x ^ { 2 } - 9 x + 20 = \right.$$
$x=3\text{, }y=3\text{, }z=2$
$x=2\text{, }y=2\text{, }z=6$
