1. D
2. A
3. C
I'll answer the last two in a minute.
Answer:
It means that you have a function that every time you input a value of x gives you 3 . If x=45 then y=3 ...if x=−1.234 then, again, y=3 and so on!
Step-by-step explanation:
Answer: 
Step-by-step explanation:
Given
The highest temperature recorded is 
The lowest temperature recorded is 
The amount of change between the high and the low temperatures is

Answer:
She spent 17 books
Equation: 45+6 = 51 and 51/3 = 17 books