$$\left. \begin{array} { l } { | \frac { 5 } { 3 } + \frac { - 7 } { 6 } | } \\ { | x \times y | = | x | y | } \end{array} \right.$$
$x=0\text{, }y<0\text{, }z=\frac{1}{2}=0.5$
$x\in \mathrm{R}\text{, }y\geq 0\text{, }z=\frac{1}{2}=0.5$
