Question

One line passes through the points (1,9) and (4,-9). Another line passes through points (6,5) and (8,-5)

Answer 1

M1=(-9-9)/4-1
m1=-18/3
m1=-6

m2=(-5-5)/8-6
m2=-10/2
m2=-5

since the slopes m1#m2 so the two lines are not parallel -5#-6

since the slopes m1#-(1/m2) then the two lines are not perpendicular either -5#-1/-6

Answer 2

M = 9 + 9 / 1 - 4
m = 18 / - 3
m = - 6

m = 5 + 5 / 6 - 8
m = 10 / - 2
m = - 5

- 6 × m2 = - 1
m2 = 1/6

therefore the lines is not parallel and perpendicular