Question 1174699
your inequality is 60x + 120y <= 1200.


x = the number of kilograms of fish.
y = the number of kilograms of chicken.



two other inequalities that need to be observed are:


x >= 0
y >= 0



when x = 0, the inequality becomes 120y <= 1200.
solve for y to get y <= 1200/120.
simplify that to get:
y <= 10


when y = 0, the inequality becomes 60x <= 1200.
solve for x to get x <= 1200/60.
simplify that to get:
x <= 20


it appears that you have a range of values where the inequality of 60x + 120y <= 1200 is true.


those ranges are:


0 <= x <= 20
0 <= y <= 10


the inequality of 60x + 120y <= 1200 can be graphed.
using the desmos.com calculator, you would graph the inequality of 60x + 120y >= 1200.


you would also graph the inequality of x <= 0 and y <= 0.


all these inequalities being graphed are opposite the inequalities of the problem.


60x + 120y <= 1200 is graphed as 60x + 120y >= 1200
x >= 0 is graphed as x <= 0.
y >= 0 is graphed as y <= 0.


the area on the graph that is not shaded is your region of feasibility.


any value of (x,y) that is on the line of the equation of 60x + 120y = 1200 or on the line x = 0 and between the points (0,0) and (20,0) or on the line
y = 0 and between the points (0,0) and (0,20) or in the area of the graph that is not shaded is a valid point of the system of inequalities.


the graph looks like this.


<img src = "http://theo.x10hosting.com/2021/020901.jpg" >


from the graph, you can see that the point (10,7) is not part of the solution set because it is in the area of the graph that is shaded.


when x = 10 and y = 7, the inequality becomes:
(60 * 10) + (120 * 7) <= 1200 which becomes:
600 + 840 <= 1200 which becomes:
1440 <= 1200 which is not true.