line containing (2,2) and (-4,-1)
slope of that line:
m = (x2 - x1) / (y2 - y1)
m = (-4 - 2) / (-1 - 2)
m = -6/(-3)
m = 2
perpendicular to that is slope = -1/2
slope-intercept form
y = mx + b
y = (-1/2)x + b
There are an infinite number of lines perpendicular to the line containing (2,2) and (-4,-1). You can pick any value for b in the equation above and the equation will be perpendicular to the line containing (2,2) and (-4,-1).