Problem 768. Are all the three given point in the same line?

In this problem the input is the coordinate of the three points in a XY plane?

P1(X1,Y1)

P2(X2,Y2)

P3(X3,Y3)

how can we find out if all the three points are on the same line or not?

for example the points (1,1) , (-1,-1) , (0,0) are on the line y=x.

Solve

Last solution submitted on Sep 13, 2019

Massimo Zanetti on 7 Oct 2016

Line, plane, two points, three points???
I think you should put some order in your mind (and in description also) ... :)