$$\left. \begin{array} { l } { ( 7 x - 5 y ) ( x + y - 2 ) } \\ { x = 10 y = 5 } \end{array} \right.$$
$x=10y\text{, }y=-\frac{\sqrt{715z+4225}}{715}+\frac{1}{11}\text{, }z\geq -\frac{65}{11}$
$x=10y\text{, }y=\frac{\sqrt{715z+4225}}{715}+\frac{1}{11}\text{, }z\geq -\frac{65}{11}$
