Tegak lurus 3y - x + 8 = 0 dan melalui (3,-1)

[tex]3y - x + 8 = 0 \\ y = \frac{x - 8}{3} \\ [/tex]
m tegak lurus maka m1.m2=-1
M1=1/3
m2= -3
rumus pgs Y-y1=m(x-x1)
[tex]y + 1 = - 3(x - 3) \\ y + 1 = - 3x + 9 \\ y = - 3x +8[/tex]