Answer:
final answer is 6
Step-by-step explanation:
Given 
To find the difference quotient use formula



Now plug it in the formula




6
Answer:
{x\ x e U and x has a negative square root} is an empty set.
Step-by-step explanation:
If x e U, x is a negative real number, and they don't have a square root (they don't have even roots). Their square roots are complex numbers, not real ones.
Answer:
64 books
Step-by-step explanation:
The first step is to find the number of books that will fit in the shelve per foot
= 40/5
= 8
Therefore the number of books that will fit perfectly in 8-foot shelf can be calculated as follows
= 8×8
= 64
Hence 64 books would fit in 8-foot shelf