Determine which tow equations represent perpendicular line.

Question

(a) y= 3/8 x -4
(b) y= 4x - 3/8
(c) y= - 1/4 x + 3/8
(d) y= 1/4 x - 3/8

b and c.

Perpendicular lines have slopes which are negative reciprocals of each other. So 4 and -1/4 work.