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automaticloveletter

  • one year ago

Jordan wants to solve the following system using the elimination method: 2x + 3y = 10 x + y = 7 What number should the equation x + y = 7 be multiplied by to eliminate y? −2 2 −3 3

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  1. anonymous
    • one year ago
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    3

  2. anonymous
    • one year ago
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    I think

  3. anonymous
    • one year ago
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    Do you want to know how to do the problem automaticloveletter?

  4. automaticloveletter
    • one year ago
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    Yes

  5. anonymous
    • one year ago
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    ok

  6. anonymous
    • one year ago
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    The aim of the game so to speak when using the elimination method is to cancel out one of your variables. In this case we want to eliminate the y variable so we will be focusing on that variable.

  7. anonymous
    • one year ago
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    Remember when you have an equation like this:|dw:1436827766595:dw|and you subtract five on both sides to solve for y?|dw:1436827785621:dw|

  8. anonymous
    • one year ago
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    well when you put the opposite of a number underneath the original, it goes away. The y on that side is all alone.

  9. anonymous
    • one year ago
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    In your equations, we have a 3y in the first equation and then a y underneath it in the second equation. We want to get that y underneath it to be the opposite of the 3y on top. What is the opposite of 3y?

  10. anonymous
    • one year ago
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    The opposite of 3y is -3y. But we can't just stick a -3 beside the y and call it a day. "What ever you do to one side you have to do to the other". That was a quote by my math teacher that I heard at least a billion times. And it holds relevance to this problem here. To get a -3 next to the y, we have to multiply them together. We can't just multiply those two terms though, we have to multiply the entire bottom equation by -3.

  11. anonymous
    • one year ago
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    |dw:1436828207705:dw|

  12. anonymous
    • one year ago
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    Now, we have to add the two equations together. After you do this, you will get:|dw:1436828310595:dw|

  13. anonymous
    • one year ago
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    Sure enough, multiplying the entire bottom equation by -3 cancelled out the ys just like we hoped.

  14. anonymous
    • one year ago
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    Your final answer would be -3. The first person that answered was wrong. I hope you didn't follow his/her answer without testing the work first. I want to be clear: I'm not hating on that person, everyone makes mistakes. :) You just have to be careful. :)

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