The cost function has a fixed part ($40,000) and a variable part, that depends on the number of CD's (14x), so we can write the cost function as:
![C(x)=40000+14x](https://img.qammunity.org/2023/formulas/mathematics/college/7hilmt3k56cp8b9fy23dopucipl62f8l01.png)
The revenue is equal to the unit price times the number of CD's:
![R(x)=93x](https://img.qammunity.org/2023/formulas/mathematics/college/upbfz3i91jxh1yv7ft6jefm15odkgx9w1u.png)
The profit function is the difference between the revenue and the cost:
![\begin{gathered} P(x)=R(x)-C(x) \\ P(x)=93x-40000-14x \\ P(x)=(93-14)x-40000 \\ P(x)=79x-40000 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/sgrguh9bxlfjy9oo0f86zhclujw67a3jav.png)
The number of CD's that must be produced and sold to breakeven happens when C(x)=R(x) or P(x)=0, so we can write:
![\begin{gathered} P(x)=0 \\ 79x-40000=0 \\ 79x=40000 \\ x=(40000)/(79) \\ x\approx506.32\approx507 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/i4703zciu565kq1fvbcxmr818hi0y95buv.png)
Answer:
C = $40000 - $14x
R = $93x
P = $79x - $40000
The breakeven number of CD's is 507 units.