Show that the minimum of Z occurs at more than two points. Maximise $Z = x + y$, subject to$\; x$– $y\leq –1, -x + y \leq 0, x, y \geq 0.$

Question

$\begin{array}{1 1}8 \\ 19 \\ 10 \\ can\;not\;be\;determined \end{array}$