The question asks, whether the points are (1,0,-1) , (0,2,3) and (-2,1,1) and (4,2,3) are coplanar.

I let (1,0,-1) be point A

let (0,2,3) point B

let (-2,1,1) point C

let (4,2,3) point D

So vector AB, AC, AD are

than using the triple scalar product

Considering that the triple scalar product is zero, would mean that the points are coplanar, correct?

But the answer is given as though that are not coplanar