If y varies inversely as x, then we write it as:
y = k/x
where k is some constant.
If we multiply both sides of this equation by x we get an equation for k:
k = x*y
We are given that y=4 when x=7, therefore:
k = 7*4 = 28
Put this back into our original equation to get:
y = 28/x
I think it would be 18,000/900 = 20 sections
The said question is asking to choose among the following theorem would be used to prove that the triangles are congruent and base on my own understanding, I would say that the answer would be Side Side Side Theorem. I hope you are satisfied with my answer and feel free to ask for more