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InsanelyChaotic Group Title

Would anyone be so gracious as to helping me get a better understanding of the dreadful algebra!??!?!!? :) Explain, in complete sentences, how you would use the elimination method to solve the following system of equations. Provide the solution to the system. 2x + 9y = 4 3x + 7y = -7

  • 2 years ago
  • 2 years ago

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  1. Venomblast Group Title
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    1st you want to figure out which variable you want to solve

    • 2 years ago
  2. InsanelyChaotic Group Title
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    X

    • 2 years ago
  3. Venomblast Group Title
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    ok. oh n btw i replied. the answer is A!!! fromt he previous question

    • 2 years ago
  4. InsanelyChaotic Group Title
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    thank you love!!!! :)))))))))))) I got that answer after I "closed" the question box

    • 2 years ago
  5. Venomblast Group Title
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    i said it 2 times. lol anywayz let do this problem

    • 2 years ago
  6. InsanelyChaotic Group Title
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    thank you nonetheless! ok let's go!

    • 2 years ago
  7. terenzreignz Group Title
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    Hey, an intermission, if you would oblige me... if x = y, then ax = ay right?

    • 2 years ago
  8. terenzreignz Group Title
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    And if a = b and c = d then a + c = b + d Don't worry, these are relevant, we'll use them.

    • 2 years ago
  9. InsanelyChaotic Group Title
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    Thank you kind sir....! @terenzreignz

    • 2 years ago
  10. Venomblast Group Title
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    man i hate the ax=ay method

    • 2 years ago
  11. terenzreignz Group Title
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    So you have 2x + 9y = 4 From our first rule, we can get 7(2x + 9y) = 7(4) 14x + 63y = 28, let's stop here, and call this "equation 1" You also have 3x + 7y = -7 Again, from our first rule, we can get -9(3x + 7y) = -9(-7) -27x - 63y = 63, stop here again, call this "equation 2" Are you getting it so far?

    • 2 years ago
  12. InsanelyChaotic Group Title
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    Yes, I've gone thru this a time before! But one question, how did you get the "7" in 7(2x+9y)

    • 2 years ago
  13. InsanelyChaotic Group Title
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    If you don't mind me asking.....! :))

    • 2 years ago
  14. InsanelyChaotic Group Title
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    Here's a joke: Subway called, they want their 6 inch back ;)

    • 2 years ago
  15. Venomblast Group Title
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    LOL

    • 2 years ago
  16. InsanelyChaotic Group Title
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    Another joke/flattery I made up: Verizon called, they want their "SMART" phone back

    • 2 years ago
  17. terenzreignz Group Title
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    Ok... You said you wanted to solve for x first (personally, I'd have gone for y first) So, we have to somehow get rid of the y. To do that, you have to make it so that the coefficient (the number that goes beside the letter) of the y in the first equation is equal to the NEGATIVE of the coefficient of the y in the second equation. In the first equation, the coeff of y was "9" and in the second, it was "7" You need to get what's called their "least common multiple" And that's 63. 63/9 is 7, so that's what I multiply to the first equation. 63/7 is 9, so that's what I multiply to the second equation, and then I NEGATED it (multiplied it by -1)

    • 2 years ago
  18. terenzreignz Group Title
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    You'll see why this is done, when I proceed... shall I?

    • 2 years ago
  19. Venomblast Group Title
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    please do lol

    • 2 years ago
  20. InsanelyChaotic Group Title
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    oh my god....this is actually making sense!!!!! :')

    • 2 years ago
  21. terenzreignz Group Title
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    Remember our second rule? if a=b and c=d then a+c = b+d ? We'll just apply that, on a larger scale, sort of...

    • 2 years ago
  22. InsanelyChaotic Group Title
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    I remember! I will, I promise!

    • 2 years ago
  23. terenzreignz Group Title
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    All right, equation 1: 14x + 63y = 28 equation 2: -27x - 63y = 63 Remember these?

    • 2 years ago
  24. InsanelyChaotic Group Title
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    I do, yes

    • 2 years ago
  25. terenzreignz Group Title
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    Now we use the second rule, we add both expressions on the left, and equate them to the sum of the expressions on the right: 14x + 63y - 27x - 63y = 28 + 63

    • 2 years ago
  26. terenzreignz Group Title
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    Notice something?

    • 2 years ago
  27. Venomblast Group Title
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    combine like term *cough**cough*

    • 2 years ago
  28. InsanelyChaotic Group Title
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    I'm writing down the steps to refer to, but yes, I notice that in order to prolong the steps, I'll have to combine

    • 2 years ago
  29. terenzreignz Group Title
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    and...?

    • 2 years ago
  30. InsanelyChaotic Group Title
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    Get x by itself

    • 2 years ago
  31. terenzreignz Group Title
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    And then you'll have reduced it to a linear equation in one variable. Solve for x, and you're almost done! Just substitute that x which you get for the x in either one of the equations you started with, and then solve for y, and then you'll be done!

    • 2 years ago
  32. InsanelyChaotic Group Title
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    oh my....I appreciate your efforts!!

    • 2 years ago
  33. terenzreignz Group Title
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    I appreciate your appreciation; have fun! :)

    • 2 years ago
  34. InsanelyChaotic Group Title
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    I will never have fun with math, but thank you:)

    • 2 years ago
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