Answer:
The shop can cut the cost of production per sandwich to $3.75. The revenue function would then be defined as R(x)=9x.
Step-by-step explanation:
We want to make as big profit as possible by making as little sandwiches as possible. This means that we want the profit, which is to be as big as possible.
For the first choice the profit per sandwich is dollars.
For the second choice the profit per sandwich is dollars.
For the third choice the profit per sandwich is dollars.
We see here that for the second choice the profit is greatest, therefore this choice is most suitably correct.