Results 1 to 2 of 2

Math Help - Simultaneous Equation [C1]

  1. #1
    Member
    Joined
    Oct 2008
    Posts
    157

    Simultaneous Equation [C1]

    I've been going through a textbook and I've came across Simultaneous equations by this point. I can do many, such as:

    c = 7d - 2 [1]
    3c - 4d = 11 [2]

    To do this I subbed c in [2] and did this method:

    3(7d-2) - 4d = 11
    21d - 4d - 6 = 11
    17d = 17
    d = 1

    And then went back to 3c - 4d = 11
    I found that 3c = 15
    and c = 5.

    However the last question is:

    6x - 5y = 27
    3y = 1 - 5x

    Now I'm pretty sure you don't use the same method as last time so what can I do here
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Junior Member
    Joined
    Sep 2008
    Posts
    73
    Yes you can use the same substitution method you used. Just solve one of the two equations for x or y first then substitute.

    6x - 5y = 27
    3y = 1 - 5x

    i.e. let 2nd equation be y = (1/3) - (5/3)x and sub that in for y in first or solve first for y and sub into 2nd

    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. simultaneous equation help
    Posted in the Algebra Forum
    Replies: 7
    Last Post: July 3rd 2010, 07:04 PM
  2. Simultaneous equation
    Posted in the Algebra Forum
    Replies: 2
    Last Post: September 15th 2009, 05:07 AM
  3. Simultaneous equation help
    Posted in the Algebra Forum
    Replies: 1
    Last Post: February 20th 2009, 11:07 AM
  4. Simultaneous Equation
    Posted in the Algebra Forum
    Replies: 10
    Last Post: December 26th 2008, 08:11 PM
  5. Simultaneous equation help
    Posted in the Algebra Forum
    Replies: 1
    Last Post: March 24th 2007, 12:12 PM

Search Tags


/mathhelpforum @mathhelpforum