SOLUTION: Are the following lines parallel, perpendicular, or neither? L1 through (–4, –7) and (1, 3) L2 through (2, 6) and (4, 10)

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)       Log On


   

Question 37762: Are the following lines parallel, perpendicular, or neither?
L1 through (–4, –7) and (1, 3)
L2 through (2, 6) and (4, 10)
Answer by junior403(76) About Me  (Show Source):
You can put this solution on YOUR website!
We can use the slope formula to determine if these lines are parallel, perpendicular, or neither?
The slope formula is...
m+=+%28y2+-+y1%29%2F%28x2+-+x1%29+
m = slope of a line, which will determine the relationship of these two lines.
So you can plug in the points that you have...
First line: lets call (–4, –7) and (1, 3) = (x1, y1) and (x2, y2)
So...
m+=+%283+-+%28-7%29%29%2F%281+-+%28-4%29%29+ m =+%2810%29+%2F+%285%29+ m =2
So the slope of this line is 2.
Lets try the next one...
Second line: lets call (2, 6) and (4, 10) = (x1, y1) and (x2, y2)
So...
m+=+%2810+-+6%29%29%2F%284+-+2%29%29+ m =+%284%29+%2F+%282%29+ m =2
So the slope of this line is also 2.
We know that two lines that have the same slope are parallel.
I hope this helps.
Good Luck!