The profit function can be gotten using the formula below:
![P(x)=R(x)-C(x)](https://img.qammunity.org/2023/formulas/mathematics/high-school/3r9w44q173wp0f0kgyb63izfoqnf6o9s8j.png)
where R(x) is the revenue function and C(x) is the cost function.
As previously calculated, the revenue and cost functions are given to be:
![\begin{gathered} R(x)=425x \\ C(x)=315x+15600 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/rg3c8hm1sgkff66nrepgtx2gp4gt1k4kgt.png)
Therefore, the profit function is:
![\begin{gathered} P(x)=425x-(315x+15600) \\ P(x)=425x-315x-15600 \\ P(x)=110x-15600 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ul10b3ff0z355z6qxl7fkm48ib3pmfessh.png)
The profit to be made is $50,000. Equating the profit function to this amount, we can get the number of kayaks required. This is shown below:
![\begin{gathered} 50000=110x-15600 \\ 110x=50000+15600 \\ 110x=65600 \\ x=(65600)/(110) \\ x=596.4 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/rksuudb9thcsl939r917c5dvq7g18arezi.png)
Therefore, the number of kayaks that must be sold is approximately 597 kayaks to make $50,000 in profits.