Answer:
-1/2
Explanation:
y - 2x =0
Solve for y
y = 2x
This is in slope intercept
y = mx+b where m is the slope
y = 2x
m=2
The slope of the line is 2
Lines that are perpendicular are the negative reciprocals
-1/m
-1/2
The lines that are perpendicular have slopes that are -1/2