The selling price of a book is $25.00 per unit. Knowing that the cost of each book corresponds to a fixed amount of $4.00 plus $6.00 per unit, build a function capable of determining the net profit (discounted value of expenses) in the sale of x books, and the profit obtained from the sale of 500 books.

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.