Question 166611
How to determine if the equations are parallel, Perpendicular or neither ? 
1. y + 3 = 6x
-6x + y = 4 
2. 3y + 21 = 2x
2y = 10 - 3x 
3. y = -x + 8
-2x -y = 4
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Find the slope (m) of each line.  If the slope is the same, they're parallel.  If the slopes are negative inverses (m and -1/m), they're perpendicular.  Otherwise, they're neither.
1. y + 3 = 6x
-6x + y = 4 
Put into slope-intercept form, y = mx + b
y = 6x - 3
y = 6x + 4
Slope is 6 in both, so they're parallel.
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2. 3y + 21 = 2x
2y = 10 - 3x 
The coefficient term can be ignored for these problems.
3y + 21 = 2x   m = 2/3
2y = 10 - 3x   m = -3/2  Perpendicular
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3. y = -x + 8  m = -1
-2x -y = 4     m = -2  Neither