Parallel or Perpendicular Lines

What is true about the graphs of y = -4x + 6 and y = (1/4)x + 6
A.)  They are parallel 
B.)  They have the same slope
C.)  They are perpendicular
D.)  They do not intersect
E.)  They are the same line

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Slope-intercept form is y = mx + b
m is the slope
b is the y-intercept

In y = -4x + 6
slope is -4
y-intercept is 6

In y = (1/4)x + 6
slope is 1/4
y-intercept is 6

Perpendicular lines have slopes which are negative reciprocals.

-4 and 1/4 are slopes which are negative reciprocals,
therefore the two lines are perpendicular, and they
also intersect at the y-intercept since it is the same in
both equations

C.)  They are perpendicular

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