Question 1209384
Let the pointbes be A (4,2),B (8,10) and C (11,16) 

If slope of AB = slope of BC then the points are co linear



If the points are (x1,y1) &(x2,y2) and (x3,y3)


(y3-y2)/(x3-x2) = (y2-y1)/(x2-x1)

(16-10)/(11-8) = 2

(10-2)/(8-4) =2

The points are co linear