Answer:
The area of the base of the rectangular box is 2x² + 4x - 3 square units and the height is x units.
So the volume of the box can be found by multiplying the area of the base by the height:
V = (2x² + 4x - 3) x (x)
V = 2x³ + 4x² - 3x
Therefore, the polynomial expression for the volume of the box is 2x³ + 4x² - 3x.