little tip....notice how ur y coordinates are the same....this means that u have a horizontal line which is represented by y = a number...with that number being the y coordinate of ur points.
So ur equation is : y = -3 <===
** if ur x's would have been the same, it would be a vertical line represented by x = a number...with that number being the x coordinates of ur points...but thats only if ur x coordinates were the same
