Results 1 to 3 of 3

Math Help - parallel lines

  1. #1
    Newbie annabananzaa's Avatar
    Joined
    Jan 2009
    Posts
    22

    parallel lines

    write an equation of the line containing the given point and parallel to the given line.

    (8,-9)
    9x-2y=5


    can someone just help me get started on this???


    please and thanksss.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member
    Joined
    Dec 2008
    Posts
    152
    the parallel line will go through point (8,-9)

    y = kx + n

    9x - 2y = 5
    2y = 9x -5
    y = (9/2)x - 5/2 <<< the first line

    Parallel lines have the same koeficient k.
    k in your case = 9/2

    now you insert the coordinates of the point through which the parallel line will go through.

    -9 = (9/2) * 8 + n
    - 9 = 36 + n
    n = -45

    y = (9/2)x -45
    Last edited by metlx; January 26th 2009 at 09:42 AM. Reason: fixed the sign error
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,657
    Thanks
    1615
    Awards
    1
    Quote Originally Posted by annabananzaa View Post
    write an equation of the line containing the given point and parallel to the given line. (8,-9); 9x-2y=5
    Here is an easy way.
    Any line parallel to 9x-2y=5 look 9x-2y=K.
    To find K use the point x=8\;\&\;y=-9: 9({\color{red}8})-2({\color{red}-9})=({\color{red}90})
    So your line is 9x-2y=90

    Note there is a ‘sign’ error in the above reply.
    This method minimizes those type of errors.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 6
    Last Post: February 24th 2011, 01:26 AM
  2. Replies: 1
    Last Post: March 14th 2010, 01:22 PM
  3. Parallel lines
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: February 19th 2010, 11:41 PM
  4. Parallel lines
    Posted in the Geometry Forum
    Replies: 1
    Last Post: April 13th 2009, 12:42 PM
  5. Replies: 2
    Last Post: January 25th 2009, 08:41 PM

Search Tags


/mathhelpforum @mathhelpforum