A direct variation is a mathematical relationship between two variables that can be expressed by an equation in which one variable is equal to a constant times the other. In other words, a direct variation is where

.
In answer a,

, so it is a direct variation.
In answer c,

, so it is a direct variation.
In answer d,

, so it is a direct variation,
Only answer b is left, which means the answer must be 'b'.
We also know 'b' is the answer because it cannot be expressed as <span>

. Instead, it is expressed as </span>

, which is not the same thing and is therefore not a direct variation.
Hope I helped, and let me know if you have any questions :)
because there are 12 in one layer and there are 3 layers
Answer: lppkoijhuytfrdeswasdxcvbn
Step-by-step explanation:
This circle has a sector area of 17pi/2 and a central angle of 17pi/90.
So, the whole angle of the circle would be 2pi. To find the area of a sector, you can use the formula A=R*Angle
17pi/2= R* 17pi/90
R=45
A=45^2 * pi
A=90 pi or 282.6