Answer:
E. \(c(b)=4+3(b-1)\)
Step-by-step explanation:
Let b represent the number of boxes.
We have been given that Barbara buys a box of pens for $4, so the cost of 1st box will be $4.
Now the number of boxes without 1st box will be \(b-1\).
We are also told that for every additional box she buys, she gets a $1 discount, so the cost of b boxes without 1st box will be \(3(b-1)\).
The total cost of all the boxes will be cost of 1st box plus cost of b boxes.
\(\text{Total cost of boxes}=4+3(b-1)\)
Since we need to represent the total cost of the pens, c, as a function of the number of boxes (b), so our function will be:
\(c(b)=4+3(b-1)\)
Therefore, our required function is \(c(b)=4+3(b-1)\) and option E is the correct choice.
