posted by Robert .
Last number from the sample test!
A plane P passes by the coordinates:
A(1,0,-7); B(-2,-1,0); C(0,0,-3)
Using the equation of the line D:
x= 7+12t, y= -1-6t, z= 2-2t,
Find the equation of a line that's entirely part of the plane P and that is perpendicular to the line D at point Q(1,2,3)