A line passes through (2 ,8 )(2,8) and ( 3, 5 )(3,5). A second line passes through ( 4, 4 )(4,4). What is one other point that the second line may pass through if it is parallel to the first line?

1 Answer
Jul 15, 2016

One possible point would be (6,-2)(6,2)

Explanation:

A line through (2,8)(2,8) and (3,5)(3,5) has a slope of
color(white)("XXX")(Deltay)/(Deltax)=(5-8)/(3-2)=(-3)/1

Any line parallel to this will have the same slope.

Any point on a line through (4,4) with the form
color(white)("XXX")(4+k * Deltax,color(white)("XX")4+k * Deltay)
with a non-zero constant k and Deltax=1, Deltay=-3
will have a slope of
color(white)("XXX")(k * Deltay)/(k * Deltax)=(k * (-3))/(k *1)=(-3)/1
and will therefore be parallel to the line through (2,8) and (3,5)

Arbitrarily picking k=2, one such point would be
color(white)("XXX")(4+2 * Deltax,color(white)("XX")4+2 * Deltay)
color(white)("XXXXXX") = (4+2 * 1,color(white)("X")4+2 * (-3))
color(white)("XXXXXX")=(6, -2)