Fill in the blanks:
               The vector equation of the line that passes through the points (3, 4, -7) and (1, -1, 6) is ______.
The position vector of the first point (3, 4, -7) is  
And the position vector of the second point(1, -1, 6): 
 
Also, the vector equation of a line passing through two points with position vectors a and b is given by:
Thus, the required line equation is