Ok, this is probably a really easy problem, but I've been trying for 2.5 days to work on it, with no luck. Any hints would be helpful, but no answers, please.

"Given threee points (x1, y1), (x2, y2), and (x3, y3), write a program to check if all the three points fall on one straight line."

My math skills are lacking in this area, so even if I were to just do it mathematically without a computer, I would just physically plot the points and see if they fell on the same line. I know these equations, but I don't know how to fit them in to this problem:

y=mx+b

(y2-y1)/(x2-x1)

My only idea is to figure out some type of relationship that exists between (x1,y1) and (x2, y2) and see if the same relationship exists between those and (x3, y3), but I'm not sure how to go about doing that. Thanks, y'all!