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Thread: Need help with linear equations with one variable

  1. #1
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    Post Need help with linear equations with one variable

    This is the task:

    Tim's mother is three times older than Tim. In 14 years, she'll be 2 times older than him. How old are they now?

    This text needs to be converted into a linear equoation with one variable and I am supposed to calculate how old is Tim and how old is Tim's mother. I can't seem to get it right. I've tried many different combinations, but I can't.
    Please help me, cause I need the answer and I need to know how to solve these types of problems.
    Thanks in advance.
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  2. #2
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    Let "t" represent Tim's age, and "m" represent his mother's age.

    Since Tim's mother is three times older than Tim, that means m = 3t.

    In 14 years, she'll be 2 times older than him. So m + 14 = 2(t + 14).

    Can you go from here?
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  3. #3
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    Not quite. I am only allowed to use X as a variable. There is a final result which says that Tim is 14 and his mother is 42. I can't get that result. I tried doing 3X = 2 (x+14), but the result was 28. I tried with (x + 3x) + 14 = 2 (x + 14) + (x + 14) with X representing Tim's age and I got the right result, but I'm not sure if I did it right, or if it was just a coincidence. Did I get it right?
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  4. #4
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    You know that m = 3t and m + 14 = 2(t + 14).

    So surely 3t + 14 = 2(t + 14).

    Go from here.
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  5. #5
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    3x + 14 = 2 (x + 14)
    3x - 2x = 28 - 14
    x = 14

    Thanks.
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