So the attached image below is about using barycentric coordinates to solve ray-triangle intersection. I was hoping someone could clear up some of the things that were mentioned in the post.
For the most part, I do understand what P', X, and Y are.
He goes on to say that we should construct a matrix A made up of only the vectors X and Y. After this, multiplying the he says to multiple the inverse of A by P'. But A has no inverse since it's not a square matrix, correct?