Identify an equation in point-slope form for the line perpendicular to y = –2x + 8 that passes through (–3, 9).

For this case we have the following linear equation:
 
 As the lines are perpendicular, then the slope of the line is:
 
 Where,
 m: is the slope of the original line
 Substituting values we have:
 
 Rewriting:
 
 Then, the equation in point-slope form is given by:
 
 Where,
 (xo, yo): ordered pair that goes through the line.
 Substituting values we have:
 
 
 an equation in point-slope form for the line perpendicular to y = –2x + 8 that passes through (–3, 9) is: