1. The problem statement, all variables and given/known data Find the mass m of the pyramid with base in the plane z = 9 and sides formed by the three planes y = 0 and y - x = 5 and 6x + y + z = 28, if the density of the solid is given by δ(x,y,z) = y. 2. Relevant equations 3. The attempt at a solution This problem is driving me insane. It takes me about 45 minutes of algebra to evaluate this incorrectly set up integral.. I integrated y in the order dz dy dx, limits, respectively: 9 to 28-6x-y 0 to 5+x 0 to 2 Is that correct? I don't really know how to get the limits for x.. this is so hard to picture in my mind! To get 2, I solved the system 6x + y + z = 28 with z = 9 and y = 5 + x, and for 0, I just guessed. Help please!