Answer:
Practical domain:
![v\in[0,230]\ or\ 0\leqslant v\leqslant 230](https://img.qammunity.org/2020/formulas/mathematics/middle-school/uf3yerl947jodozbjjdpl6xwq34h14b0ue.png)
Roger can earn $510 at most.
Explanation:
We are given the function
![E(v)=50+2v](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mk0exfw4a3thfrof7ddzijidykjglpyinb.png)
Which gives the earnings of Roger when he sells v videos. Since the play’s audience consists of 230 people and each one buys no more than one video, v can take values from 0 to 230, i.e.
![v\in[0,230]\ or\ 0\leqslant v\leqslant 230](https://img.qammunity.org/2020/formulas/mathematics/middle-school/uf3yerl947jodozbjjdpl6xwq34h14b0ue.png)
That is the practical domain of E(v)
If Roger is in bad luck and nobody is willing to purchase a video, v=0
If Roger is in a perfectly lucky night and every person from the audience wants to purchase a video, then v=230. It's the practical upper limit since each person can only purchase 1 video
In the above-mentioned case, where v=230, then
![E(230)=50+2(230)=50+460=510](https://img.qammunity.org/2020/formulas/mathematics/middle-school/fwaniay89cl9vc10ke4kj31otft5e3cxd3.png)
Roger can earn $510 at most.