A line passes through (6 ,4 )(6,4) and (9 ,2 )(9,2). A second line passes through (3 ,1 )(3,1). What is one other point that the second line may pass through if it is parallel to the first line?

1 Answer
Jan 14, 2017

another point of the second line is: (1;7/3)(1;73)

Explanation:

A line parallel to another one has the same slope, then you can find the slope m of the first line by the following formula:

m=(Deltay)/(Deltax)=(2-4)/(9-6)=-2/3

where Deltay is the difference between the y-coordinates of the given points and Deltax is the difference between their x-coordinates.

To find another point of the second line you can choose one coordinate and find the second, depending on the chosen one:

Then if you decide, for example, to choose color(red)(x=1), you would solve:

(Deltay)/(Deltax)=(1-y)/(3-color(red)1)=-2/3

where(3;1) is the given point of the second line.

That's

3*(1-y)=-2*2

3-3y=-4

y=7/3

Then another point of the second line is: (1;7/3)