Question 57242
Hi Ashley,
I need to determine which two equations represent perpendicular lines:

 (a)  y = 5/8 x -3   (b)  y = 3x - 5/8   (c)  y = -1/3 x + 5/8  (d)  y = 1/3 x - 5/8
The slope intercept form of a line is: {{{highlight(y=mx+b)}}}, where m=slope and (0,b)=y-intercept.
Perpendicular lines have slopes that are negative reciprocals of each other.  They have opposite signs and are upside down.
(a) has a slope of 5/8
(b) has a slope of 3, which can be written as 3/1
(c) has a slope of -1/3
(d) has a slope of 1/3
:
(b) and (c) have slopes that are opposite signs and upside down, they are perpendicular.
Happy Calculating, Ashley!!!