Answer:
The maximum is at point 5,0
Explanation:
These graphs are set up so that one of the intersection points is going to give you either a maximum or a minimum.
The first thing you have to do is graph the 4 constraints. I use a graphing program like desmos.
Put your 4 equations in from top to bottom. The quadrillateral defined by the intersect points I have labeled and 0,0 define the area that contains the intersect points of the 4 graphs.
Now take the intersect points and show the calculations for C
C = 6x - 4y
Point (0,0)
C = 6*0 - 4*0
C = 0
Point (0,3)
C = 6(0) - 4*3
C = - 12
Point (1.5,3.5)
C = 6*(1.5) - 4*(3.5)
C = 9 - 14
C = - 5
Point (5,0)
C = 6*(5) - 4*(0)
C = 30
The maximum is produced from point 5,0