Direct variation is of the form y=kx (inverse variation is of the form y=k/x)
We have

So

The rational term vanishes as <em>x</em> gets arbitrarily large, so we can ignore that term, leaving us with

and this happens if <em>a</em> = 1 and <em>b</em> = -1.
To confirm, we have

as required.
To find the answer, to convert a improper into mixed, first take the denominator (9) and find how many times it can go into the numerator (16) FULLY. The answer is 1 time. 1 is the whole number. Then whatever is leftover is the new numerator, and the old denominator is the same. So your answer is 1 7/9
Hope this helps!