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Math Help - Solve systems by substitution

  1. #1
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    Solve systems by substitution

    These substitution equation is really frustrating me what is the purpose of these equation I don't see how they are part of every day life.
    Anyway any help on this equation is very helpful.


    8x 4y = 16
    y = 2x 4
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  2. #2
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    Quote Originally Posted by Patience View Post
    These substitution equation is really frustrating me what is the purpose of these equation I don't see how they are part of every day life.
    Stop complaining. You should see the math I do. I purposely choose it so that I can have no meaning in real life. Think of it as abstract expressionism.

    Anyway any help on this equation is very helpful.


    8x 4y = 16
    y = 2x 4
    8x-4y=16
    y=2x-4

    Thus,

    8x-4(2x-4)=16

    8x-8x+16=16

    16=16

    Which is true.

    That means there were infinitely many solutions to that equation.

    Thus, if x=t (some number) then the second equation tells us that,
    y=2t-4.

    Thus,

    x=t
    y=2t-4.

    For any number t.
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