Final answer:
The equation to find the total cost, c, of making necklaces is given by c = 12.50 + 3.25n, where 12.50 is the initial start-up cost and 3.25 is the cost per necklace.
Step-by-step explanation:
To find the total cost, c, for making a certain number of necklaces, n, we need to consider both the initial start-up cost and the additional cost per necklace. We are given that the start-up materials cost $12.50, which is a fixed cost. Additionally, each necklace costs $3.25 to make, which is a variable cost depending on the number of necklaces made.
The total cost (c) consists of the fixed start-up cost plus the variable cost that depends on the number of necklaces (n). This results in a linear equation:
c = 12.50 + 3.25n
Where 12.50 represents the start-up cost and 3.25n represents the total variable cost for n necklaces. Simply, the total cost is the sum of the fixed start-up cost and the cost of producing each necklace multiplied by the number of necklaces made.