( 717, #45) Determine whether the planes 2x + 4y - 2z = 1 and -3x - 6y + 3z = 10 are parallel, perpendicular, or neither

( 717, #45) Determine whether the planes 2x + 4y - 2z = 1 and -3x - 6y + 3z = 10 are parallel, perpendicular, or neither. If neither, find the angle between them.
Solution:
The normal vectors of the planes are n1 = < 2, 4, -2 > and n2 = < -3, -6, 3 >. The two vectors are proportional to each other by a factor of -3/2, thus the planes are parallel to each other.

by: nl