The answer is 7.85
First, you divide the diameter by two to get the radius (2.5) and then you multiply by pi(3.14) to get 7.85
Start with the first sentence, and the definition of the area of a rectangle:
l * w = 36
Rewrite the equation to get
l = 36 / w
or
w = 36 / l
Either one shows the inverse relationship between w and l.
Assuming the last part wants you to write an equation for an x-y graph, the equation would be
y = 36 / x
The greatest common factor of those numbers is 8.
