SOLUTION: Help me please figure this out. I don't get it??? Are the following lines parallel, perpendicular, or neither? L1 through (–4, –7) and (1, 3) L2 through (2, 6) and (4, 1

Algebra ->  Equations -> SOLUTION: Help me please figure this out. I don't get it??? Are the following lines parallel, perpendicular, or neither? L1 through (–4, –7) and (1, 3) L2 through (2, 6) and (4, 1      Log On


   

Question 73811: Help me please figure this out. I don't get it???
Are the following lines parallel, perpendicular, or neither?
L1 through (–4, –7) and (1, 3)
L2 through (2, 6) and (4, 10)
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Call the slopes m%5B1%5D and m%5B2%5D
They are parallel if m%5B1%5D+=+m%5B2%5D
They are perpendicular if m%5B1%5D+=+-1%2Fm%5B2%5D
Now find the slopes, which is (change in y) / (change in x)
m%5B1%5D+=+%28-7+-+3%29+%2F+%28-4+-+1%29
m%5B1%5D+=+-10+%2F+-5
m%5B1%5D+=+2
m%5B2%5D+=+%286+-+10%29+%2F+%282+-+4%29
m%5B2%5D+=+-4+%2F+-2
m%5B2%5D+=+2
m%5B1%5D+=+m%5B2%5D, so the lines are parallel