There isn’t an answer because you haven’t provided us enough data
Answer:
See Below.
Step-by-step explanation:
We want to show that the function:

Increases for all values of <em>x</em>.
A function is increasing whenever its derivative is positive.
So, find the derivative of our function:
![\displaystyle f'(x) = \frac{d}{dx}\left[e^x - e^{-x}\right]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20f%27%28x%29%20%3D%20%5Cfrac%7Bd%7D%7Bdx%7D%5Cleft%5Be%5Ex%20-%20e%5E%7B-x%7D%5Cright%5D)
Differentiate:

Simplify:

Since eˣ is always greater than zero and e⁻ˣ is also always greater than zero, f'(x) is always positive. Hence, the original function increases for all values of <em>x.</em>
Answer:
Let p represent the # of pages in the book. Then, Nora has already read 0.30p pages and has 0.70p pages left to read.
If she reads 25% pages/night, that means reading 0.25(0.70)p pages per night, or 17.5 pages/night. If 28% p/n, that means 0.28(0.70)p pages/night, or 19.6p pages/night.
How many nights will it take Nora to finish the book if she reads 25% of 7/10 of the book per night? Without any calculations, we can answer this by "4 nights, since she reads 1/4 of the unread portion of the book per night."
If she reads 28% of 7/10 of the book per night, that will require fewer nights:
First night: 28%
Second night: 28%
Third night: 28%
Total: 3(28%) = 84%
This leaves 16% to read on the final night.
This is one interpretation of what I think is a poorly worded question.
The author of this question might have meant reading 25% of the remaining unread pages per night, which leads to a different answer.
Differentiate the function.
d
d
x
[
243
x
10
,
5
]
Answer:880
Step-by-step explanation: They need to cover expense of $13200. If printing fee is $25 and they sell the books for $40 each, then that means when selling a book they cover expense of printing plus they earn $15 per book.
So if they earn $15 per book that means they have to sell 13200/15=880 books to break even.
If you want to solve this by using equation the this would look like this:
expenses: $13200 + $25x where x is number of books sold
earnings: $40x
Equation:
13200+25x=40x
13200=15x
x=880