$$\left. \begin{array} { l } { y \lt x - 4 } \\ { y \geq \frac { 3 } { 5 } x + 4 } \end{array} \right.$$
$x\in (y+4,\frac{5(y-4)}{3}]\text{, }y>16$
$y\in [\frac{3x}{5}+4,x-4)\text{, }x>20$
