14. ABC is a triangle with vertices A(-2, 2, 3), B(2, 2, 5), and C(0, 0, 9). Determine AB x AC . 15. Find the volume of the parallelepiped defined by the vectors a = (0,1,2) , b = (1,2,3) and c = (2,3,4). 16. Consider the following vector expression (2a-b) . (c x d) + 5 Describe in words each operation and determine the nature (scalar or vector) of the result