Fd the volume of the given solid under the plane x - 2y

Question

1. Evaluate the double integral.

∫∫_D 3y² dA, D is the triangular region with vertices (0, 1), (1, 2), (4, 1).

2. Find the volume of the given solid.

Under the plane x - 2y + z = 9 and above the region bounded by x + y = 1 and x² + y = 1.

3. Find the volume of the given solid.

Under the surface z = 5xy and above the triangle with vertices (1, 1), (4, 1), and (1, 2)