A) Determine the boundary limits of the following regions in spaces. The region D₁ bounded by the planes x + 2y + 3z = 6 and the coordinate planes. The region D₂ bounded by the cylinders y = x² and y = 4 - x², and the planes x + 2y + z = 1 and x + y + z = 1. The region D3 bounded by the cone z² = x² + y² and the parabola z = 2-x² - y² The region D4 in the first octant bounded by the cylinder - x² + y² = 4, the paraboloid z = 8 - x2 - y² and the planes x = y, z = 0, and x = 0. B) Calculate the following integrals JJJ. dV, y dV JJJ.* xy dV, [11. D4 dV,