SOLUTION: Are the following lines parallel, perpendicular, or neither? L1 through (–4, –7) and (1, 3) L2 through (2, 6) and (4, 10) a)Parallel b)Perpendicular c)Neither The ans

Algebra ->  Graphs -> SOLUTION: Are the following lines parallel, perpendicular, or neither? L1 through (–4, –7) and (1, 3) L2 through (2, 6) and (4, 10) a)Parallel b)Perpendicular c)Neither The ans      Log On


   

Question 68580: Are the following lines parallel, perpendicular, or neither?
L1 through (–4, –7) and (1, 3)
L2 through (2, 6) and (4, 10)
a)Parallel
b)Perpendicular
c)Neither
The answer I got for this one was perpendicular. Is this correct? If not could you show me how to do this the right way. Thanks.
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Remember the rule?
"Perpendicular lines have slopes that are the negative reciprocal of each other."
"Parallel lines have identical slopes"
So first, we need to find the slopes of the lines through the given points.
Using the slope formula: m+=+%28y2-y1%29%2F%28x2-x1%29
For the first slope, (x1, y1) = (-4, -7) and (x2, y2) = (1, 3)
m1+=+%283-%28-7%29%29%2F%281-%28-4%29%29 Simplify.
m1+=+%283%2B7%29%2F%281%2B4%29
m1+=+10%2F5
m1+=+2
Similarly for the second slope, m2.
m2+=+%2810-6%29%2F%284-2%29 Simplify.
m2+=+4%2F2
m2+=+2
Well, as you can see, the slopes of the two lines are identical which means that the lins are parallel.
You might want to review your work on this problem!