Determine whether the lines L1 and L2 passing through the pa

Determine whether the lines L1 and L2 passing through the pairs of points are parallel, perpendicular, or neither. L1: (2, 9), (-7, 3) L2: (-1, -1), (4, 7/3)

Solution

slope of L1:

m1 = (y2-y1)/(x2-x1)

   = (3-9)/(-7-2)

= -6/-9

    = 2/3

slope of L2:

m2 = (y2-y1)/(x2-x1)

   = (7/3 + 1)/(4+1)

= 10/15

   = 2/3

since m1 =m2

they are parallel