Answer:
You have to buy more than 20 books to make Cool Cover Bookstore club a better deal.
Step-by-step explanation:
Given that:
Fee charged by Fun Reads Bookstore = $40
Charges per book = $5
Let x be the number of books.
A(x) = 5x+40
Fee charged by Cool Covers Bookstore = $100
Charges per book = $2
B(x) = 2x+100
For making Cool Cover Bookstores club a better deal,
B(x) > A(x)
2x+100 > 5x+40
2x-5x > 40-100
-3x > -60
Dividing both sides by -3

Hence,
You have to buy more than 20 books to make Cool Cover Bookstore club a better deal.
Answer:
y=8-x or y=9-x or y=243-x (The spot where the 8 is can be any number as long as the number infront of the 0 is still -1)
Step-by-step explanation:
Answer : Option D is correct i.e [2.5,4]
Explanation :
Suppose our function is f(x)
then the value of f(x) is minimum where
it reaches -0.44 and 3 with two different intervals .
As we know that for finding the local minimum ,
the criteria is that f'(x)=0 .
So, here
f'(-0.44)=0 and
f'(3)=0
both are the local minimum point for the function f(x)
but -0.44 is the global minimum point .
In our case for [2.5,4] is the required interval where f(x) reaches its local minimum.