$2x=yz_{2}\text{ and }yz_{2}=1$

$x=\frac{1}{2}=0.5$
$y=\frac{1}{z_{2}}\text{ and }z_{2}\neq 0$

$z_{2}=\frac{1}{y}$
$x=\frac{1}{2}\text{ and }y\neq 0$