the plane x+y=4 crosses the y=0 plane at y=4 and crosses the x=0 plane at x= 4
I can see that the bounded region is in the first octant. the question is looking for the intervals of integration for x,y,z. I get a surface with 5 faces. all my other problems up to this point I was able to slice with a plane which then allowed me to have a 2-space coordinate system so that I could find the intervals. In this I don't know where to slice and it seems I would need to slice it a couple or more ways to get everything or I am over complicating it.