Question

Write an appropriate inverse variation equation if y = 9 when x = 4.

Answer 1

let the reqd equation be of the form
y = k/x
we just need to know k the constant of proportionality

Answer 2

thus k=xy
as y = 9 when x = 4.
k=9*4 =36
hence eq becomes y=36/x

Answer 3

I almost had it! Omg thank you so much, Tough problem answerd by a great person. I thought it was 46

Answer 4

Here's a handy list of how to construct the variation equations:

"x varies directly with y" => y = kx
"x varies inversely with y" => y = k/x
"x varies jointly with y and z" => x = kyz

in all cases, there's a k, though the value of k may be 1.

Answer 5

and if you see something like "y varies inversely with x squared" you just plug that in, too: y = k/x^2