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Math Help - Need help

  1. #1
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    Need help

    How do I solve the followinf equation using the elmination method?

    p = 28 +q
    3p = -9q+120
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  2. #2
    Rhymes with Orange Chris L T521's Avatar
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    Quote Originally Posted by mathdummy22 View Post
    How do I solve the followinf equation using the elmination method?

    p = 28 +q
    3p = -9q+120
    First rewrite it as

    \begin{array}{rcrcr}p&-&q&=&28\\3p&+&9q&=&120\end{array}

    I noticed that if you divide the second equation through by 3, you end up with this system:

    \begin{array}{rcrcr}p&-&q&=&28\\p&+&3q&=&40\end{array}

    I would like to eliminate p. Thus, multiply the first equation by -1 and then add the equations together:

    \begin{array}{rcrcr}-p&+&q&=&-28\\p&+&3q&=&40\end{array}\implies 4q=12\implies \color{red}\boxed{q=3}

    Can you find p?

    --Chris
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  3. #3
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    will p = 31 ?
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  4. #4
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    Reply

    • Yes. Did you get it now???
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  5. #5
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    I do, but not entirley for fractions. I posted another question
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