Since the bounds of x are given we will save those for last (keeping with the definition of the triple integral)
So all we need to find is our y bounds and we have 2 equations of y in terms of x, no problem!
We need to determine which of the following is greater on the interval
Clearly the first equation is greater
Now you need to re-write for
Clearly we need to find constant values for z and get x/y in terms of z which should be no problem. Compute both and compare