a perpendicular line will have a negative reciprocal slope. All that means is " flip " the slope and change the sign. So if we have a slope of 1 or 1/1. our perpendicular line needs a slope of -1.
y - y1 = m(x - x1)
slope(m) = -1
(1,-5)...x1 = 1 and y1 = -5
now we sub...pay close attention to ur signs
y - (-5) = -1(x - 1)....not done yet
y + 5 = -1(x - 1)...or it can also be written as : y + 5 = - (x - 1)
