Let price of one scarf be $x
Price of the other is 3 more than $x
Therefore price of the other scarf =$x +3
The total price she paid = $25.00
That is, x+x+3=25
2x+3=25
2x=25-3
2x=22
x=22/2
x=11
The price of one scarf is $11 and the price of the other is 11+3=$14
The price of the expensive scarf =$14.
The fraction is 12/1000 which simplified to 3/250. The percentage is 1.2%.
Answer:
Part A) see the explanation
Part B) 
Step-by-step explanation:
Part A)
we know that
A relationship between two variables, x, and C, represent a proportional variation if it can be expressed in the form
or 
Let
C ---> is the total cost (represent the output or dependent variable)
x ----> is the number of books (represent the input or independent variable)
In this problem
we have a proportional relationship between the variables x and C
Part B) we know that
The linear equation is given by

The constant of proportionality k is the same that the slope or unit rate of the linear equation
In this problem the constant k is given

so

For x=12 books
substitute in the equation and solve for C

In function notation
