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Math Help - Proof by Condradiction

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    Proof by Condradiction

    Glad I found this site. Here is my first post. I really am unsure of where to start all of this new material is confusing me. Please help.

    1.
    (a) Assume that n is a positive integer. Use the proof by contradiction method to prove:

    If 7n + 4 is an even integer then n is an even integer.
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  2. #2
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    Quote Originally Posted by premierplayer View Post
    1.[/FONT](a) Assume that n is a positive integer. Use the proof by contradiction method to prove:
    If 7n + 4 is an even integer then n is an even integer.
    Assume that 7n+4 is even and n is odd.
    Now an odd times an odd is odd. An odd plus an even is odd.
    There is a contradiction in there somewhere. Can you find it?
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  3. #3
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    Quote Originally Posted by premierplayer View Post
    1.[/FONT](a) Assume that n is a positive integer. Use the proof by contradiction method to prove:
    If 7n + 4 is an even integer then n is an even integer.
    Assume that 7n+4 is even and n is odd.
    Now an odd times an odd is odd. An odd plus an even is odd.
    There is a contradiction in there somewhere. Can you find it?
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