Use the graphical method to demonstrate that the follow$-$

ing model has no feasible solutions.

Maximize Z $=5$x$1+7$x$2,$

$82$ CHAPTER $3$ INTRODUCTION TO LINEAR PROGRAMMING

subject to

$2$x$1$ x$2<=1$

$$x$1+2$x$2<=1$

and

x$1>=0,$ x$2>=0.$