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anonymous

  • 4 years ago

Solve using the elimination method 7x + 7y = 7 x + 2y = 2 pleas explain I do not get this at all

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  1. Akshay_Budhkar
    • 4 years ago
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    ok let us go step by step

  2. anonymous
    • 4 years ago
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    step one is do divide the first equation by 7 to make your life simpler. you get \[x+y=1\] and now i shut up

  3. Akshay_Budhkar
    • 4 years ago
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    \[7x + 7y- 7 \therefore x+y =1 \therefore x=y-1\]

  4. precal
    • 4 years ago
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    7x+7y=7 x+2y=2 The goal is to eliminate the x's or the y's It is your choice

  5. precal
    • 4 years ago
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    or you could mutiply -7 to the second equation

  6. anonymous
    • 4 years ago
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    ok now i put in my two cents again. says "elimination" not "substitution" although i would use the second method as well

  7. precal
    • 4 years ago
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    Technically the method does not matter but since it did say elimination it is better to cancel out the x's or the y's I am choosing to get rid of the x's by multiplying -7 to equation 2

  8. Akshay_Budhkar
    • 4 years ago
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    substituting that in equation 2 we have\[\begin {array} x x+2y=2 \\ y-1+2y=2 \\ 3y=3 \\ y=1 \end {array}\]

  9. Akshay_Budhkar
    • 4 years ago
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    opps my bad

  10. Akshay_Budhkar
    • 4 years ago
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    didnt read elimination sorry

  11. Akshay_Budhkar
    • 4 years ago
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    ok in this you can solve by subtracting the two equations that is x+y=1 and x+2y=2.. you get 2y-y=2-1 therefore y=1

  12. anonymous
    • 4 years ago
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    ok I am so confused

  13. anonymous
    • 4 years ago
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    ok I get it sorry didnt get it at first

  14. Akshay_Budhkar
    • 4 years ago
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    so is it fine now?

  15. anonymous
    • 4 years ago
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    Yes it is thank you so much I get it now i hope

  16. Akshay_Budhkar
    • 4 years ago
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    if u have any doubt clear it =D all the best

  17. anonymous
    • 4 years ago
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    Thank you :)

  18. anonymous
    • 4 years ago
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    I thought it would be 2y-y=2/1

  19. anonymous
    • 4 years ago
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    there for y=2

  20. precal
    • 4 years ago
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    I will do it for you using elimination

  21. anonymous
    • 4 years ago
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    i just need the process explained to me it just is not clicking im sorry

  22. precal
    • 4 years ago
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    7x+7y=7 x+2y=2 7x+7y=7 -7(x+2y=2) 7x+7y=7 -7x-14y=-14 add equations together -7y=-7 divide by -7 to both sides y=1 x+2y=2 x+2(1)=2 x+2=2 -2 both sides x=0 solution x=0 and y=1

  23. anonymous
    • 4 years ago
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    ok this makes since to me thank you

  24. anonymous
    • 4 years ago
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    so this would be and infanite solution correct because it would graph as the same line not two intersecting line?

  25. precal
    • 4 years ago
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    Another name for this method is called multiplication and addition method First you pick a number to multiply one of the equations then you add both equations together goal is to get rid of the x's or the y's that is why is is called elimination. If you wanted to get rid of the the y's instead you would have to multiply 2 to the first equation and then -7 to the second equation this will produce 14y and -14y and then you would have solve for x first. Many ways to eliminate x's or y's

  26. precal
    • 4 years ago
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    No this is one solution because we were able to find the point of intersection

  27. anonymous
    • 4 years ago
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    oh ok so what would a infanite solution look like?

  28. anonymous
    • 4 years ago
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    sorry to ask so many questions, but I really want to grasp this and I am having a really hard time

  29. precal
    • 4 years ago
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    infinite solutions is the same line given in multiple form example x+y=4 2x+2y=8 did you notice they are the same I only multiply 2 to the original equation

  30. anonymous
    • 4 years ago
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    yes I see

  31. precal
    • 4 years ago
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    No solution is 2 parallel lines, they never cross. look for same slopes y=2x+3 y=2x+6

  32. anonymous
    • 4 years ago
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    thank you so much for explaining this I understand it so much better now than i did from the book

  33. precal
    • 4 years ago
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    The number of solutions is determined by the number of times the equations cross: One solution means they cross in one place (X,Y) No solution means they do not cross (Parallel lines) Infinitely many solution means they cross in many places (because they are the same line)

  34. anonymous
    • 4 years ago
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    Thank you so much

  35. precal
    • 4 years ago
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    Anytime :)

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