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Math Help - Find two numbers where difference is 20 & the sum is -4

  1. #1
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    Question Find two numbers where difference is 20 & the sum is -4

    Find 2 numbers such that the difference between them is 20 and their sum is -4.

    Is there a systematic way or method to solve this besides just guessing integers?

    (p.s. No algebra allowed, this is a pre-algebra questions)
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  2. #2
    A Plied Mathematician
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    The only systematic way to solve this that I know of is to use linear algebra:

    x - y = 20
    x + y = -4.

    Turn the crank.
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  3. #3
    Junior Member RHandford's Avatar
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    Hi

    A clue, one of the numbers you want is 8, can you work out the other number?
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  4. #4
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    Divide the difference equally between the two numbers.

    Half of 20 is 10, half of -4 is -2. Add and subtract -2 to and from 10.

    Think about what the signs should be.

    (As Ackbeet implies "systematic" pretty much means algebra!)
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  5. #5
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    Quote Originally Posted by Kick View Post
    Find 2 numbers such that the difference between them is 20 and their sum is -4.

    Is there a systematic way or method to solve this besides just guessing integers?

    (p.s. No algebra allowed, this is a pre-algebra questions)
    Two simultaneous equations is a systematic way towards solving that type of problem.
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