Arthur wants to make a raised rectangular frame, shown below, to grow basil plants. The basil plants are transplanted, with their soil, from 2-in.-wide pots into the frame. The diagram at the right below shows a top-down view of the frame. Each circle represents a transplanted basil plant with its soil. Arthur will add more soil to the frame until the soil is 3x in. deep. A cuboid with a height of 3x inches. A rectangle with six circles of two inches diameter placed at equal distance in two rows consisting of three circles each. The distance between each circle and the sides of the rectangle is marked as x inches. Write a polynomial function V to represent the volume of soil in the frame in terms of x. Explain.