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Math Help - point of intersection

  1. #1
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    point of intersection

    find the point of intersection of the lines: 3x + 4y = -6 and 2x + 5y = -11
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  2. #2
    Senior Member euclid2's Avatar
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    Quote Originally Posted by heatherblack87 View Post
    find the point of intersection of the lines: 3x + 4y = -6 and 2x + 5y = -11
    3x + 4y = -6
    2x + 5y = -11

    use elimination multiply the first by -2 and the second by three

    (3x + 4y = -6)*-2
    (2x + 5y = -11)*3

    -6x-8y=12
    6x+15y=-33

    cancel the x's

    -8y=12
    15y=-33

    7y=-21
    y=-21/7
    y=-3

    now sub to find x
    Last edited by euclid2; December 8th 2008 at 07:55 PM.
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  3. #3
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    Quote Originally Posted by euclid2 View Post
    3x + 4y = -6
    2x + 5y = -11

    use elimination multiply the first by -2 and the second by three

    (3x + 4y = -6)*-2
    (2x + 5y = -11)*3

    -6x-8y=12
    6x+15y=-33

    cancel the x's

    -8y=12
    15y=-33

    7y= - 21
    y= - 21/7
    y= - 3

    now sub to find x
    Small corrections in red.
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  4. #4
    Senior Member euclid2's Avatar
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    Quote Originally Posted by mr fantastic View Post
    Small corrections in red.
    I appreciate that, no wonder when i subed the y value the answer was so chaotic, lol
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