Graph the system of inequalities and list each corner point. $$\left\{ \begin{array}{r@{}r@{}r} 3 x+ 13 y & \ge & 42 \cr 25 x+ y & \ge & 28 \cr y & \ge & 0 \cr x & \ge & 0 \end{array} \right.$$
Corner Points:
If there is more than one corner point, type the points separated by a comma i.e.: (1,2),(3,4).

Determine the maximum value of $z=5 x+ 3 y$ subject to the given system of linear inequality constraints. Input DNE if it does not exist

Determine the minimum value of $z=5 x+ 3 y$ subject to the given system of linear inequality constraints. Input DNE if it does not exist