LP graphical solution: Look at the linear programming problem below:

Max Z $=20$ x$1+30$ x$2$

Subject to:

$10$ x$1+5$ x$2<=600($C$1)$

$6$ x$1+20$ x$2<=600($C$2)$

$8$ x$1+10$ x$2<=600($C$3)$

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

Solve it using the graphical method by answering the questions below:

a$)$ Draw lines for the constraint functions C$1,$ C$2$ and C$3,$ as well as the objective function

$($iso$-$cost$)!$

b$)$ Put a mark on the feasible area!

c$)$ Determine the optimal point!

d$)$ If the inequality sign C$2$ is reversed $($from the $<=$ sign changed to $>=),$ describe the

graphical results and what is the solution to this new formulation?

e$)$ If the problem in point $($d$)$ changes the objective function $($from "max" to "min"$),$

describe the graphical results and what is the solution to this new formulation?