Lines PQ and RS are perpendicular. Find x. P(1, −3); Q(3, 3); R(x, 6); S(8, 5) x =

Question

Lines PQ and RS are perpendicular. Find x.

P(1, −3); Q(3, 3); R(x, 6); S(8, 5)

x =  

Answer 1

slope of PQ = (-6)/(-2) = 3

slope of RS = (6-5)/(x-8) = 1/(x-8)

they are negative reciprocals of each other so:

3 = 8-x

x+3 = 8

x = 5