Answer:
Your answer is D.
Step-by-step explanation:
If you need explanation ask me in comment
Answer:
All real numbers
Step-by-step explanation:
21 - 7x = 7(3 - x)
21 - 7x = 21 - 7x
Since both sides of the equation are equal, the answer is all real numbers.
Given:
The table of values is
Number of Students : 7 14 21 28
Number of Textbooks : 35 70 105 140
To find:
The rate of change and showing that the ratios of the two quantities are proportional and equivalent to the unit rate.
Solution:
The ratio of number of textbooks to number of students are




All the ratios of the two quantities are proportional and equivalent to the unit rate.
Let y be the number of textbooks and x be the number of students, then

Here, k=5.


Hence the rate of change is constant that is 5.
I think D is the correct answer.