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Solving first and second degree equations

  1. May 23, 2016 #1
    1. The problem statement, all variables and given/known data

    solve the equations below


    1.) 2x -1 = (1/2) *x +3

    and

    2) 1/x - 4/ x2= 0

    2. Relevant equations
    3. The attempt at a solution



    2x -1 = 0,5x +3

    2x= 0,5x +4
    1,5x = 4
    x= 4/ 1,5
    x= 8/3

    my math teacher told me that the x= 8/6 would have been correct solution to this first one



    1/x -4/ x2 = 0

    1/x = 4/x2

    we enlarge the fraction 1/x

    x/ x2 = 4/ x2

    multiply both sides by x2

    x= 4

    singular solution assuming that originally x is unequal to 0 (because cannot divide with 0)

    my teacher told me that this latter equation has twin solutions either x=-4 or x= 4

    plugging -4 into the original equation, this seems not true at all...

    -0,25 -( 0,25) = 0

    -0,5 = 0

    untrue.
     
  2. jcsd
  3. May 23, 2016 #2

    ehild

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    Your solutions are correct.
     
  4. May 23, 2016 #3
    Thank you for prompt response. It looks like even math teachers make silly mistakes sometimes. Twice in this problem sheet.

    Can you take a gander at my other thread about algebra problem that I had. I just posted a simple word problem in the same precalculus homework math subrofum
     
  5. May 23, 2016 #4

    ehild

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    I see you solved it.
     
  6. May 23, 2016 #5

    SteamKing

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    Time to find another math teacher. :sorry: :rolleyes: :mad:
     
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