# of Reams of paper: x
# of ink Cartridges: y
Cost of a ream of paper: $6
Cost of an ink cartridge: $18
Total cost: T=6x+18y
The maximum total cost is $234
T=6x+18y<=234
when x=0→6(0)+18y<=234
0+18y<=234
18y<=234
18y/18<=234/18
y<=13
(x,y)=(0,13): Possible options: Graph B, C, or D
when y=0→6x+18(0)<=234
6x+0<=234
6x<=234
6x/6<=234/6
x<=39
(x,y)=(39,0): Graph B
Answer: Graph B
