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anonymous

  • one year ago

Solve the following system of equations using any method 3x+14y=−78 12x+12y=84

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  1. anonymous
    • one year ago
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    What do you think the solution is?

  2. anonymous
    • one year ago
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    i have no clue, can you help?

  3. anonymous
    • one year ago
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    Have you done simultaneous equations before?

  4. anonymous
    • one year ago
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    i dont think so

  5. anonymous
    • one year ago
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    Have you solved simple equations like 4x = 8?

  6. anonymous
    • one year ago
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    yes

  7. anonymous
    • one year ago
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    You'll be fine then.

  8. jdoe0001
    • one year ago
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    well... if you haven't covered "system of equations", how are you expected to solve it then?

  9. jdoe0001
    • one year ago
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    or using what "method" are you expected to solve it, that is, what chapter is this covering?

  10. anonymous
    • one year ago
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    What you need to do is simple, you just rearrange one of the equations so you have y or x on one side of the equation. Can you do that?

  11. anonymous
    • one year ago
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    Then I can take you through the next step after that.

  12. anonymous
    • one year ago
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    Lets solve for y first 3x+14y=−78 12x+12y=84 Times the top equation by -4 3x+14y=−78 -4(3x+14y)=−78 *-4 -12x - 56y= 312 Now you have a new equation and you can use the cancellation method to solve. Solve for y. Can you finish? -12x - 56y = 312 12x + 12y = 84

  13. jdoe0001
    • one year ago
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    if you haven't covered the material, I'd think this exercise doesn't apply to you then and your teacher should know better than to assign material he/she hasn't covered so... you may want to do that first

  14. jdoe0001
    • one year ago
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    can we do it for you? sure, do we know how to? yes does that help you? nope

  15. anonymous
    • one year ago
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    @lindsey_quick are you still with me?

  16. anonymous
    • one year ago
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    We have this now. -12x - 56y = 312 12x + 12y = 84 To solve for y we can use the cancellation method. -12x and 12x will cancel out because -12x + 12x = 0x = 0 so now we have the following equations -56y = 312 12y = 84 Can you finish solving for y ???

  17. anonymous
    • one year ago
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    i got 5.57 and 7 ?

  18. anonymous
    • one year ago
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    -56y = 312 12y = 84 What does -56y + 12y = ?

  19. anonymous
    • one year ago
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    -44y

  20. anonymous
    • one year ago
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    Correct!! Now what does 312 + 84 = ?

  21. anonymous
    • one year ago
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    396

  22. anonymous
    • one year ago
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    Correct!!! So -56y = 312 12y = 84 -56y + 12y = -44 and 312 + 84 = 396 so we have now -44y = 396 Now we need to get y by its self. since -44y is multiplication, we divide each side by - 44 \( \huge \frac{-44y}{-44} = \frac{396}{-44} \) \( \huge y = \frac{396}{-44} \) What do you get when you divide 396 by -44?

  23. anonymous
    • one year ago
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    9

  24. anonymous
    • one year ago
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    Close, you forgot your - symbol but yes -9. Ok we found our y value to the solution now to find the x value just put the y value into one of the original equation and solve for x. I am going to use 3x+14y=−78 3x+14(-9)=−78 Can you solve for x or do you still need a little help?

  25. anonymous
    • one year ago
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    i think i got it from here , thanks

  26. anonymous
    • one year ago
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    3x+14(-9)=−78 3x -126 = - 78 3x -126 + 126 = - 78 + 126 3x = -78 + 126 3x = 48 \( \huge \frac{3x}{3} = \frac{48}{3} \) \( \huge x = \frac{48}{3} \) \( \huge x = 16 \) So the solution is ( 16, -9) Good job! Practice makes perfect. Keep working at them and you will be a pro at them!!!

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