Question

Barbara buys a box of pens for $4. For every additional box she buys, she gets a $1 discount. Which expression represents the total cost of the pens, c, as a function of the number of boxes, b?

Answer 1

c = f(b) = 4b – 1 ?

Answer 2

@Nnesha

Answer 3

If Barb bought only one box, what did she pay?
If she bought 2 boxes, what did she pay?
If she bought 10 boxes, what did she pay?
Each of these situations identifies a value for b and the corresponding value for c. Use these values in each alternative one-at-a-time until you find the one that fits in all situations.