Final answer:
The correct equation to find the total cost (y) for x pens with a one-time graphic design fee and a cost per pen is y = 2.5x + 57. This equation combines the fixed cost and the variable cost per pen.
Step-by-step explanation:
The student is asking for an equation to calculate the total cost (y) of purchasing x pens with a one-time fee and an additional per pen cost. Given the information that each pen costs $2.50 and there is a one-time graphic design fee of $57.00, the equation that relates the number of pens (x) to the total cost (y) is:
y = 2.5x + 57
This equation takes into account the variable cost of the pens, which is $2.50 per pen, represented by the term 2.5x, and the fixed cost, which is the one-time fee for the graphic design, represented by the constant 57 added to the total cost.