Find the volume beneath z fxy and above the region describe

Find the volume beneath z = f(x,y) and above the region described by the rectangle with vertices (0,0), (4,0), (4,2), and (0,2).

f(x,y) = 4x² + 9y²

Hint: Compute the double integral required to find the volume under f(x,y) using the limits of integration given by the region on the x-y plane.