Hello, First I will post my question: It has been quite a while since my last calculus course so I don't remember everything. Now here is MY question: How do I find the equation of the plane in which the region E lies below? I know from the solution manual that the E is the region that lies below the plane 2z + 6x + 3y = 6 How do I find that out? I found three separate equations for each plane - xy, yz, xz. 6 = 2z + 6x, 6 = 2z + 3x, 6 = 3y + 6x. And I can see the relationship between all four planes. How do I come up with the final equation of the plane 2z + 6x + 3y = 6 I should know this. I just can't remember. Any help is appreciated. Thankyou.