The variables x and y vary inversely. which equation relates x and y when x=9 and y=3

Since x & y vary inversely (it means when x increases, y decreases & vice versa)

Then the equation==> y = k/x (k is a constant to be calculated)

But x=9 and y=3 (given) = = > 3=k/9 or k=27 & the equation becomes y=27/x