Solution:
It is given that: and the constraints
Taking , we have
Now, plotting all the constrain equations it can be seen that the shaded area is the feasible region determined by the constraints.
The area is feasible. Therefore, maximum value will occur at the corner points
On evaluating the value of , we obtain
It can be seemn from the above table that the maximum value of is
So, the maximum value of is 4 at .