Final answer:
The volume of the cube with a side length X = 9 units is 729 cubic units, calculated by cubing the side length (9³).
Step-by-step explanation:
If X = 9 units, then the volume of the cube can be calculated using the formula for the volume of a cube, which is V = s³ where s is the length of a side of the cube. In this case, s = 9 units, so the volume V would be:
V = 9 units × 9 units × 9 units = 729 cubic units
Therefore, the volume of the cube is 729 cubic units.