P=(3,-2,-2) Q=(3,-3,-3) und R=(1,-3,-2)
PQ = [0, -1, -1]
PR = [-2, -1, 0]
N = PQ ⨯ PR = [-1, 2, -2] = - [1, - 2, 2]
E: (X - [3, -2, -2]) * [1, - 2, 2]/|[1, - 2, 2]| = 0
E: (X - [3, -2, -2]) * [1/3, - 2/3, 2/3] = 0
Ist d bei euch [3, -2, -2]·[1/3, - 2/3, 2/3] = 1 ?