Answer:
Id say its C!
Because in mm, a human hair on average is 70 mm's thick
Have a wonderfull day :D
1. y=f(x)=170x-4 is a function with variable x representing a year.
2. Let's consider the difference between 2 consecutive years, say year 3 and year 4
f(3)=170*3-4
f(4)=170*4-4
we expect f(3)-f(4) to be 4 since after 4 years, the water will be 4 feet less than after 3 years.
check: f(3)-f(4)=(170*3-4)-(170*4-4)=170*3-4-170*4+4=170*3-170*4=170*(3-4)=170*(-1)=-170

Plug in A = 13

Add 1 to both sides:

Divide 2 to both sides:

Find the cube root of both sides:
![\sf~b=\sqrt[3]{7}](https://tex.z-dn.net/?f=%5Csf~b%3D%5Csqrt%5B3%5D%7B7%7D)
Which best describes the diameter of a circle?
<em>Statements</em>
<u><em>A. The distance from the center to any point of the circle</em></u>
This statement describes the radius of the circle
<u><em>B. The length of a chord that contains the center of the circle</em></u>
This statement describes the diameter of the circle
<u><em>C. The distance around the circle</em></u>
This statement describes the circumference of the circle
<u><em>D. The length of a chord that does not contain the center of the circle</em></u>
This statement describes a line segment linking any two points on a circle that does not contain the center of the circle
therefore
<u>the answer is the option</u>
B. The length of a chord that contains the center of the circle