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Math Help - system of equations

  1. #1
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    system of equations

    ok so i suck at this even though its simple...i tend to over think these things....your help would be much appreciated

    2p-3q=6
    -2p+3q=-6
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  2. #2
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    It is easy, but you need to find either p or q first and use it to solve for the other one. So, if you have
    <br />
2p-3q=6<br />
    -2p+3q=-6<br />
    Say you want P for the first equation so you have to get P on one side alone...

    2p-3q=6<br />

    Divide out your 2 to get P alone.
    2p/2=6/2+3q/2

    Which reduces to p=3+3q/2

    Now, you have P so find Q by putting the value of P in the other equation...
    -2(3+3q/2)+3q=-6 and I think you can figure out the rest.
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  3. #3
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    Ok, first you take equation 2 and solve for one of the variables.

    Let's solve for 'p'.

    -2p+3q=-6
    -2p=-3q-6
    2p=3q+6
    p=3/2q+6/2
    p=1.5q+3

    Now, take the equation and plug it into the variable of the first equation.

    2p-3q=6

    2(1.5q+3)-3q=6

    Now solve the equation for 'q'.

    q=1

    Now, plug 'q' into the first equation.

    2p-3q=6
    2p-3(1)=6
    2p-3=6
    2p=9
    p=4.5

    Plug in 'p' and 'q' to check you answers in a equation (it doesn't matter if its the ist or second equation.)

    Let's use the first since it look the easiest.

    2p-3q=6

    2(4.5)-3(1)=6 ?

    9-3=6 ?

    6=6

    The answers are equal so you know your answers work.

    Hope this helps.
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