We need to maximize the function Z = 4x + 3y
Converting the given inequations into equations, we obtain
3x + 2y = 160, 5x + 2y = 200, x + 2y = 80, x = 0 and y = 0
Region represented by 3x + 2y ≥ 160:
The line 3x + 2y = 160 meets the coordinate axes at A1603,0 and B(0, 80) respectively.
By joining these points we obtain the line 3x + 2y = 160.
Clearly (0, 0) does not satisfies the inequation 3x + 2y ≥ 160.
So, the region in xy plane which does not contain the origin represents the solution set of the inequation 3x + 2y ≥ 160.
Region represented by 5x +2y ≥ 200:
The line 5x + 2y = 200 meets the coordinate axes at C(40, 0) and D(0, 100) respectively.
By joining these points we obtain the line 5x + 2y = 200.
Clearly (0, 0) does not satisfies the inequation 5x +2y ≥ 200.
So, the region which does not contain the origin represents the solution set of the inequation 5x +2y ≥ 200.
Region represented by x +2y ≥ 80:
The line x + 2y = 80 meets the coordinate axes at E(80, 0) and F(0, 40) respectively.
By joining these points we obtain the line x + 2y = 80.
Clearly (0, 0) does not satisfies the inequation x + 2y ≥ 80.
So, the region which does not contain the origin represents the solution set of the inequation x + 2y ≥ 80.
Region represented by x ≥ 0 and y ≥ 0:
Since, every point in the first quadrant satisfies these inequations.
So, the first quadrant is the region represented by the inequations x ≥ 0, and y ≥ 0.
The feasible region determined by the system of constraints 3x + 2y ≥ 160,5x+2y ≥ 200, x +2y ≥ 80, x ≥ 0, and y ≥ 0 are as follows.

Here, we see that the feasible region is unbounded.
Therefore,maximum value is infinity.