Determine if the points A(2, 6), B(-1, 0) and C(5, 12) are collinear.
What is the slope of $\displaystyle \overleftrightarrow {AB}~?$ What is the slope of $\displaystyle \overleftrightarrow {AC}~?$
@brosnan123, you have posted several questions with on evidence that you have made any effort whatsoever.
This is not a homework service.
Post some of your own work.