Answer:
Part A: C(x) = 0.068x+0.8
Part B: 1.28
Part C: 9.76
Explanation:
Part A:
The cost C equals
cost = revenue - profit
![C(x)=R(x)-P(x)](https://img.qammunity.org/2023/formulas/mathematics/college/fvhm0pa70k7pwfzqlamf35kxuh7wjc117k.png)
which is
![C(x)=0.15x-(0.082x-0.8)](https://img.qammunity.org/2023/formulas/mathematics/college/iinozgz84f65g6k7gtdu5hao8hpqruzk6e.png)
![C(x)=0.15x-0.082x+0.8](https://img.qammunity.org/2023/formulas/mathematics/college/gd7rkmrcvm6e6uxins51d17do0pgzzxd1t.png)
![\boxed{C\mleft(x\mright)=0.068x+0.8}](https://img.qammunity.org/2023/formulas/mathematics/college/xuvhdxahj5afb9ftqsgtrdlz4qfdd0h823.png)
Part B:
The cost of producing 7 units is found by putting in x = 7 into the above equation. This gives
![C(7)=0.068(7)+0.8](https://img.qammunity.org/2023/formulas/mathematics/college/dcmwzt0x1cuh2xvnid5mxnijllxpwu182n.png)
![C(7)=1.28](https://img.qammunity.org/2023/formulas/mathematics/college/mbtf7iehoil05x4suihmlswz14191miqyd.png)
Hence, the cost of producing 7 items is 1,28 million dollars.
Part C:
To break even, the cost must equal the revenue
![R(x)=C(x)](https://img.qammunity.org/2023/formulas/mathematics/college/zscgm3yc44shd5yodwbfs9xlixy7wuon4x.png)
or
![0.15x=0.068x+0.8](https://img.qammunity.org/2023/formulas/mathematics/college/zhzsrqcvto1b2225pbtf14upg0139xykna.png)
subtracting 0.068 from both sides gives
![0.082x=0.8](https://img.qammunity.org/2023/formulas/mathematics/college/qm5a16zec6zsal6hl3kacgrq7hlas5xkc2.png)
dividing both sides by 0.082 gives
![\boxed{x=9.76}](https://img.qammunity.org/2023/formulas/mathematics/college/1ajnm17d9c995utzqn57x19x525ip3atfu.png)
which is the break-even point