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

Answer:
the answer is 6.72
Step-by-step explanation:
Instead of a diagram you can do 4.2 times 1.6 and after you finishes doing that You put the decimal 2 times and you should get 6.72
Well, if Sameer's plum was 32 calories, and we know his total snack was 56 calories, all we have to do is:
56-32=24
24 / 4 = 6
Sameer ate one plum (32Kcal) and 6 strawberries (4Kcal each)
Answer:
The answer to your question is 
Step-by-step explanation:
Here, there is a difference of squares, so just solve it and simplify

Multiply the binomials
= 1 - 
Simplify
= 
= 
They are all even numbers and divisible by 2