Results 1 to 2 of 2

Math Help - simultaneous equation

  1. #1
    Member
    Joined
    Jun 2009
    Posts
    105

    simultaneous equation

    could you please help me solve this simultaneous equation

    -3x+y=15<br />
          x=2-2y
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Behold, the power of SARDINES!
    TheEmptySet's Avatar
    Joined
    Feb 2008
    From
    Yuma, AZ, USA
    Posts
    3,764
    Thanks
    78
    Quote Originally Posted by johnsy123 View Post
    could you please help me solve this simultaneous equation

    -3x+y=15<br />
x=2-2y

    Just FYI Tex editor's don't recognize white space inside math tags so that is really hard to understand.

    -3x+y=15
    x=2-2y

    subbing the 2nd equation into the first gives

    -3(2-2y)+y=15 \iff -6+6y+y=15 \iff 7y=21 \iff y =3

    Now sub in to find x x=2-2(3)=-4 so the solution is

    (-4,3)
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. simultaneous equation
    Posted in the Algebra Forum
    Replies: 8
    Last Post: September 21st 2009, 04:25 AM
  2. simultaneous equation
    Posted in the Algebra Forum
    Replies: 2
    Last Post: August 23rd 2009, 11:57 AM
  3. simultaneous equation
    Posted in the Algebra Forum
    Replies: 3
    Last Post: August 19th 2009, 06:02 AM
  4. simultaneous equation
    Posted in the Algebra Forum
    Replies: 5
    Last Post: August 18th 2009, 06:26 PM
  5. Simultaneous ln and e equation!
    Posted in the Algebra Forum
    Replies: 1
    Last Post: March 11th 2007, 07:20 AM

Search Tags


/mathhelpforum @mathhelpforum