SOLUTION: Decide whether the pair of lines is parallel, perpendicular, or neither. The line through (-20, 5) and (-4, 7) and the line through (-5, 5) and (7, 4)

Algebra ->  Graphs -> SOLUTION: Decide whether the pair of lines is parallel, perpendicular, or neither. The line through (-20, 5) and (-4, 7) and the line through (-5, 5) and (7, 4)       Log On


   

Question 44203: Decide whether the pair of lines is parallel, perpendicular, or neither.

The line through (-20, 5) and (-4, 7) and the line through (-5, 5) and (7, 4)


Answer by adamchapman(301) About Me  (Show Source):
You can put this solution on YOUR website!
you have two sets of x and y coordinates (x1, y1) and (x2, y2)
x1=-20
y1=5
x2=-4
y2=7
Below is an EXTREMELY important equation:
%28y-y%5B1%5D%29%2F%28y%5B2%5D-y%5B1%5D%29=%28x-x%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29
Put your values in:
%28y-5%29%2F%287-5%29=%28x%2B20%29%2F%28-4%2B20%29
%28y-5%29%2F2=%28x%2B20%29%2F16
y-5=%282x%2B40%29%2F16
y=%282x%2B40%29%2F16%2B5
y=x%2F8%2B7.5
y=0.125x%2B7.5 This is the equation of the first line.
Follow the same process for the second line and you should get the equation y=50%2F9-x%2F9
Then do these checks to find the relationships betweenthe lines:
The gradients of the two lines are NOT equal, so they are NOT PARALLEL.
The gradient of the second line is NOT the negative inverse of the first line's gradient, so they are NOT PERPENDICULAR.
So the lines are neither parallel nor perpendicular.
This should be clear by observing the graphed functions below.
+graph%28+500%2C+500%2C+-15%2C+2%2C+0%2C+11%2C+0.125x%2B7.5%2C+50%2F9-x%2F9%29+
I hope this helps
P.S. I am trying to start up my own homework help website. I would be extremely grateful if you would e-mail me some feedback on the help you received to adam.chapman@student.manchester.ac.uk