How do we use inverse variation?

First, lets list ALL the interger dimensions for rectangles whose area is 24
                            L           |         W
                               1                 24
                               2                 12
                               3                  8
                               4                  6
                               6                  4
                               8                  3
                              12                 2
                              24                 1
This relationship is called an Inverse Variation.
We say that x varies inversely with y.
       xy = 24                       when x goes up, y goes down.
       y = 24/x                      when y goes up, x goes down.

If x varies inversely as y and x = 12 when y = 3, what is the value of x when y = 9?
                     xy = k                            
12*3 = k
k would equal 26

x*9 = 36
  9        9
x would equal 4