Answer
It is necessary to have approximately 183,000 visitors in order to sell 300 books.
Work Step by Step
1. Let's try to substitute the number of sell books and solve for "x" in the first function:
$s(x) = 1.55x$
$300 = 1.55x$
$\frac{300}{1.55} = \frac{1.55x}{1.55}$
$193.55 = x$
- But, that equation is only valid if $0 \leq x \leq 100$, and 193.55 is greater than 100. Therefore, we will have to use the second equation:
$s(x) = 1.75x - 20$
$300 = 1.75x - 20$
$300 + 20 = 1.75x$
$\frac{320}{1.75} = \frac{1.75x}{1.75}$
$183 \approx x$
- 183 is between 100 and 250, therefore, the result is valid.
- Therefore, it is necessary to have approximately a total of 183,000 visitors in order to sell 300 books.
