a) They ask to the cost function, and we know that there is a fixed cost of 18000 and that each canoe cost 20 to produce it, then we can write it mathematically as:
![c(x)=20x+18000](https://img.qammunity.org/2023/formulas/mathematics/college/umo8zld9phfkzt65j7xaml2ohzmex3obli.png)
b) The revenue function is given by the selling price, which is 80, and the number of canoes sold, then we can write it mathematically as:
![r(x)=80x](https://img.qammunity.org/2023/formulas/mathematics/college/tweil1bwvo1h77mezf8cu2k0i65vxyhtwp.png)
c) the break-even point is given when the revenues cover the costs, then is the intersection point of the two functions:
![20x+18000=80x](https://img.qammunity.org/2023/formulas/mathematics/college/uj3hr521or8c8ld6cq93o0g9k0vnw411id.png)
![60x=18000](https://img.qammunity.org/2023/formulas/mathematics/college/ms2tqk8nq2qxjg8h8xp3ax04zlvodv2a1h.png)
![x=300](https://img.qammunity.org/2023/formulas/mathematics/college/d1ehu0nnfhzyhwp6p6mt883vcsd1n5vl83.png)
And we can replace it to find the other component:
![y=80x=80\ast300=24000](https://img.qammunity.org/2023/formulas/mathematics/college/66us0ic3g2dxlp59jkeleiwgjy2bqmdmr6.png)
So we can conclude that the break-even point is when is sold 300 canoes and the costs and the revenues are the same, that is $24000