Write an equation for a line perpendicular to y = 3 x − 1 and passing through the point (9,1).

Question

y=?

Answer 1

y=3x-1 has a perpendicular line with a negative inverse slope

y=-x/3 +b

plug in the point to solve for b

(9,1)

1=-9/3+b

b=1+3=4

y=-x/3 +4