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Math Help - Algebra

  1. #1
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    Algebra

    Can you guys help me out with this one question?

    -4x+3y=17
    3x-2y=10

    What are x and y?
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  2. #2
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    Quote Originally Posted by Rocher View Post
    Can you guys help me out with this one question?

    -4x+3y=17 .... (1)
    3x-2y=10 .... (2)

    What are x and y?
    Multiply equation (1) through by 3.
    Multiply equation (2) through by 4.

    Now add the two new equations together to eliminate x. Solve for y.

    Substitute your value of y into either of (1) or (2) and solve for x.
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  3. #3
    Member FalconPUNCH!'s Avatar
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    -4x+3y=17
    3x-2y=10

    What you do is add the two equations together to cancel out some terms, but before you do that you'll need to get some of terms equal to each other.

    2(-4x + 3y = 17)
    3(3x - 2y = 10)

     -8x + 6y = 34
     9x - 6y = 30



    you can double check to see if I did the math correctly. yeah I did something wrong sorry. I dont' have a calculator on hand right now.
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  4. #4
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    Quote Originally Posted by FalconPUNCH! View Post
    -4x+3y=17
    3x-2y=10

    What you do is add the two equations together to cancel out some terms, but before you do that you'll need to get some of terms equal to each other.

    2(-4x + 3y = 17)
    3(3x - 2y = 10)

     -8x + 6y = 34
     9x - 6y = 30

    You add the two equations up and the 6y cancel and you get this:

     x = 64

    plug x into one of the equations and solve for y

    -4 (64) + 3y = 17 Mr F edit: Corrected the equation.
    -256  + 3y = 17 Mr F edit: Added the negative and corrected the value.
     3y = 273 Mr F edit.
     y =91 Mr F edit: Corrected value of y.

    you can double check to see if I did the math correctly. yeah I did something wrong sorry. I dont' have a calculator on hand right now.
    FalconPUNCH! decided to eliminate y first. That's OK.

    You can double check the answers by eliminating x first (see my earlier reply).
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