SOLUTION: How do I find out if the following lines are perpendicular, parallel or neither? L1 through (-4,-7) and(1,3) L2 through (2,6) and (4,10)

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Question 80715: How do I find out if the following lines are perpendicular, parallel or neither?
L1 through (-4,-7) and(1,3)
L2 through (2,6) and (4,10)
Found 2 solutions by Earlsdon, josmiceli:
Answer by Earlsdon(6098) About Me  (Show Source):
You can put this solution on YOUR website!
You can do this by finding the slopes m+=+%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 of the two lines.
If the slopes are equal, the lines are parallel, if the slopes are the negative reciprocal of each other, the lines are perpendicular.
L1:
m%5B1%5D+=+%283-%28-7%29%29%2F%281-%28-4%29%29
m%5B1%5D+=+%283%2B7%29%2F%281%2B4%29
m%5B1%5D+=+10%2F5
m%5B1%5D+=+2
L2:
m%5B2%5D+=+%2810-6%29%2F%284-2%29
m%5B2%5D+=+4%2F2
m%5B2%5D+=+2
As you can see, the slopes are equal so this means that the lines are parallel!

Answer by josmiceli(6781) About Me  (Show Source):
You can put this solution on YOUR website!
Find slope, m, of each, then decide.
m%5B1%5D+=+%283+-+%28-7%29%29+%2F+%281+-%28-4%29%29
m%5B1%5D+=+10+%2F+5
m%5B1%5D+=+2
----------------
m%5B2%5D+=+%2810+-+6%29+%2F+%284+-+2%29
m%5B2%5D+=+4+%2F+2
m%5B2%5D+=+2
The slopes are the same, so L1 and L2 are parallel