Answer:
The minimum value of C is 20
Explanation:
we have
----> constraint 1
----> constraint 2
----> constraint 3
----> constraint 4
using a graphing tool
The solution is the shaded area
see the attached figure
To find the minimum value of C evaluate the vertices (9,2) and (12,0) of the solution area in the objective function
so
For x=9, y=2 --->
For x=12, y=0 --->
therefore
The minimum value of C is 20