SOLUTION: Determine if the pair of lines are parallel, perpendicular, coincident, or none of the above. x + 2y = -24 -6x + 3y = 21 and please explain how you can tell by just

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Question 709502:
Determine if the pair of lines are parallel, perpendicular, coincident, or none of the above.

x + 2y = -24
-6x + 3y = 21
and please explain how you can tell by just loooking! thank you

Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
Determine if the pair of lines are parallel, perpendicular, coincident, or none of the above.
x + 2y = -24
-6x + 3y = 21
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Solve each for "y":
y = (-1/2)x - 12
slope = -1/2 ; y-int = -12
------------------------------
y = 3x + 7
slope = 3 ; y-int = 7
-------------------------------
Since the slopes are not equal the lines are not parallel or coincident.
Since the product of the slopes is not -1, the lines are not perpendicular.
-----
By looking:
ax + by = c
dx + ey = f
----
If a/d = b/e and a/d is not equal to c/f the lines are parallel.
If a/d = b/e = c/f the lines are coincident
-----
If a/d is not equal to b/e the lines intersect at one point.
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Cheers,
Stan H.
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