I was given this question for hw and I am pretty confused. It asks: Show that the determinantal equation

det[

x y z 1

x1 y1 z1 1

x2 y2 z2 1

x3 y3 z3 1 ]

=0

is an equation for the plane though the three non collinear points (x1, y1, z1), (x2, y2, z2) and (x3, y3, z3).

Any help is really appreciated.