Question 78914: How do I find the slope of any line parallel to the line through points (9, 6) and (1, 2).
Answer by bucky(2189)   (Show Source):
You can put this solution on YOUR website! Given two points: (9, 6) and (1, 2).
.
Parallel lines all have the same slope. So for this problem all you have to do is to find
the slope of the line that connects the two given points.
.
Call point (9, 6) point 1. Then  and  . Similarly, call point
(1, 2) point 2. Then  and  .
.
The equation for the slope of the line joining two given points is:
.
.
All you have to do is to substitute the values as we identified them above. When you do
the equation becomes:
.
.
So the slope of the line joining points (9, 6) and (1, 2) is  . That means
that any line parallel to that line will also have a slope of .
.
If you had identified the points in the other order ... calling point (9, 6) point 2
and point (1, 2) point 1, the values that you would substitute into the equation for slope
would switch in position, but the answer would still be so it doesn't matter
which is point 1 and which is point 2. You just have to be careful that 
is the x value in the point you called point 1,  is the x value in the point you
called point 2,  is the y value in the point you called point 1, and  is
the y value in the point you called point 2. Then plug those values into the the correct
positions as shown in the equation:
.
.
and you will get the answer.
.
Hope this helps you understand a little more about slope and parallel lines.
|
|
|
