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Homework Help: 2s Complement with hex

  1. Apr 11, 2010 #1
    1. The problem statement, all variables and given/known data

    Which is 2s complement of 0x3D9E

    a) BD9F
    b) BDA0
    c) C262
    d) 3D9E

    2. Relevant equations

    I believe I subract each digit from F

    3. The attempt at a solution

    FFFF
    -3D9E
    ______
    C261

    Someone in my class said the answer was c) but do I still add one? I remember the saying "reverse the bits and and one" does that still apply?

    Tjvelcro
     
  2. jcsd
  3. Apr 11, 2010 #2
    You are computing 16's complement, not twos complement. And yes, you add 1 at the end to get the answer.
     
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