Question

Determine whether the points (1, 5) (2, 3) and (-2, -11) are collinear.

Answer 1

it is easy. either find area of triangle formed by these point if area comes zero then points are collinear otherwise not.
or
you can also find slope of 2 case if it came same then points will be collinear otherwise not.

Answer 2

Hope you find it helpful