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Math Help - Solve a pair of intersecting lines

  1. #1
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    Solve a pair of intersecting lines

    Hi there,

    Can anyone offer some advice on how one would go about solving this equation? I can't figure it out!

    (x+2)(y+2)+(x-3)(y+2)=0


    Thanks in advance,

    Josh
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  2. #2
    Senior Member jakncoke's Avatar
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    Re: Solve a pair of intersecting lines

     (x+2)(y+2) + (x-3)(y+2) = 0 only when  (x+2)(y+2) = 0 and  (x-3)(y+2) = 0
     (x+2)(y+2) = 0 when x = -2 or y = -2
     (x-3)(y+2) = 0 when x = 3 or y = -2
    y=-2 is the only one which makes both eqn 0, so y = -2 is the soln.
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  3. #3
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    Re: Solve a pair of intersecting lines

    Hi Dave,

    Thanks for your reply.

    That makes sense but I'm wondering if there's an algebraic methodology I can use? I know that the other solution is x=0.5, so can I do the following:

    Ignore (y+2) and (y+2) so you have
    X + 2 + x - 3
    = 2x -1
    X = -0.5

    This comes out, but doesn't seem like its the correct way to go about it!
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