9. Give a geometrical interpretation of the intersection of the planes with equations xty+z+3=0 2x + 3y - 6z - 1 = 0 4x + 6y -12z + 11 = 0 10. Determine a scalar equation for the plane that passes through the point (1, 1, 4) and is perpendicular to the line of intersection of the planes x + 2y + z = 1 and 2x + y + 3z = 3.11. A line has the equation r = s(1,0,0) and a plane has the equation y=1. a) Describe the line. b) Describe the plane