Maximize $Z = x + y,$ subject to$x - y \le - 1, - x + y \le 0,x,y \ge 0$ .

.: The system of constraints is :

$x - y \le - 1$ …(1)

$- x + y \le 0$ ….(2)

$x,y \ge 0$ ….(3)

Let ${l_1}:x - y = - 1; \& {l_2}; - x + y = 0$

Clearly, there is no feasible region.
[ There is no common region]

Hence, there is no maximum value of Z

Exercise - 12.2