Find the coordinates of the foot of perpendicular of point $3\mathbf{i}+\mathbf{j}-9\mathbf{k}$ to

Question

Find the coordinates of the foot of perpendicular of point $3\mathbf{i}+\mathbf{j}-9\mathbf{k}$ to the plane $3x+y-z=-3$

Accepted Answer

$(-3,-1,-7)$

Vectors - Perpendicular Projection and Reflection in a Plane