I have the problem mostly done but this last part of the integration is getting to me. So we originally had a triple integral that I had to integrate with respect to z. The limits were from -(sqrt(13-4x^2))/3 and to the positive of that. So we ended up getting (z^3)/3 to plug in the limits to and, after simplifying, we have (2(13-4x^2)^3/2)/81 and I have to take that with respect to x. I simplified it a bit further and now am down to 26/81 on the outside to be multiplied in and (-8x^2 (sqrt(13-4x^2)) needing to be integrated. I was thinking substitution to get the sqrt to be u but then we would still be left with an x when we pull out the -8xdx. I was also thinking of doing it by part but I'm not sure if that would work either. Bah.