Answer:
The relationship between the circumference of a circle and its diameter represent a direct variation and the constant of proportionality is equal to the constant 
Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form 
where K is the constant of proportionality
In this problem we know that
The circumference of a circle is equal to

therefore
the relationship between the circumference of a circle and its diameter is a direct variation and the constant of proportionality is equal to the constant 
Answer:
33
Step-by-step explanation:
I say 33, because of the 11 times table
Amount charged for downloading individual songs = x dollars
Amount charged for downloading an entire song album = y dollars
Person A:
6x + 2y = 25.92
3x + y = 12.96
y = 12.96 - 3x
Person B:
4x + 3y = 33.93
Putting the value of y from the first equation in the second we get
x = 0.99 dollars
Putting the value of x in the first equation we get
y = 12.96 - 3x
= 12.96 - 2.97
= 9.99 dollars
125 = 5^3 = 25 * 5

The simplification you are trying to do involves finding the prime factorization of a number. Since 125 is not divisible by 2, move on to 3. 125 is also not divisible by 3, so move on to 5. Then 125/5 = 25, and 25/5 = 5, so 125 = 5^3. The prime factorization of 125 is 5^3.