Question 1152496
here's the graph.


<img src = "http://theo.x10hosting.com/2020/021401.jpg" alt="$$$" >


anything in the area that's not shaded is possible.
also anything on the lines that enclose the non shaded area are posible since the inequality includes equal as well (<= not <)(>= not >).
the points that fit the requirements have been noted.
they are shown in (x,y) format.
the inequality is 600 <= 200x + 150y <= 1200
for example, the point (3,4) is possible since 200 * 3 + 150 * 4 = 600 + 600 = 1200 which is the upper limit of what's possible.
likewise, the point (0,4) is possible since 200 * 0 + 150 * 4 = 600 which is the lower limit possible.
likewise, the point (2,4) is possible since 200 * 2 + 150 * 4 = 400 + 600 = 1000 which is above 600 and less than 1200.
the value of x and y have to be integers since only whole boats can be sold.